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#1 sayhello   User is offline

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How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 13 April 2020 - 11:16 AM

How To Fix A Blank WordPress Admin Panel




update - update': since a second site behaves exactly the same way - i guess that i have to look for the server-conditions.. perhaps i look for this one here Increase PHP Memory Limit Sometimes, a blank screen occurs because WordPress runs out of memory.
i will do so and keep you informed... ;)/>/>/>




full story: hello dear experts on DreaminCode.


hello dear WP-experts and user among the user of Dreamincode. Yesterday i just installed WP 5.4 (freshly) on a new page – new db and to spell it out clearly on a own root-server.

i did some fsj-test und produced some hammering of the site: http://www.f-s-j.de can be called and has got no errors – all displays well. So we can state: first of all: the freshly installed page looks well at the index-page.

if you proceed and try to login then the login page shows up well also!! No problem untill here. From the login panel the site loads: http://www.f-s-j.de/wp-admin/index.php but this page is broken in other words – it is blank!

i get back the following on the page:


the page - http://www.f-s-j.de/wp-admin/index.php has got no data: it is a blank page with the following error code:
ERR_EMPTY_RESPONSE



but all the rest works well – i e no problem in accessing
and here we encounter issues:

http://www.f-s-j.de/...www.f-s-j.de%2F
http://www.f-s-j.de/...n/nav-menus.php
http://www.f-s-j.de/...?post_type=page
http://www.f-s-j.de/wp-admin/edit.php
http://www.f-s-j.de/...dmin/upload.php
http://www.f-s-j.de/...it-comments.php
http://www.f-s-j.de/wp-admin/users.php
http://www.f-s-j.de/wp-admin/tools.php


but i encounter some issues: i allmost evey time get a blank WordPress Admin Panel: http://www.f-s-j.de/wp-admin/index.php

question: How To Fix A Blank WordPress Admin Panel

i found some possible fixes: https://www.fixrunne...panel-is-blank/

but first of all – did any body of you also encounter such issues?!?

again: i found some possible fixes: https://www.fixrunne...panel-is-blank/

How To Fix A Blank WordPress Admin Panel

Quote

Check if your host is having problems :: Problems from your host may often lead to a blank WordPress admin panel. If, for example, you have 2 websites on the same host, and you are experiencing this problem across both websites, you can be almost certain it is your host. You should first check with your host to see if they are having problems, or are getting similar complaints from other users. If that’s the case, you can choose to wait for the problem to be resolved, or better yet, upgrade to a managed, reliable, WordPress hosting service. If you decide to switch, we highly recommend you use WP Engine managed hosting service. This service is robust and reliable and will help you avoid whatever security, data loss, or any other situation that could lead to a blank panel.

Disable Active Theme
In many cases, a blank WordPress admin panel results from code errors in your currently active theme. You can resolve this by disabling this theme. However, since you cannot access your dashboard to do this, you have to disable your theme manually using FTP. Please follow the steps below:
First, access your WordPress files using FTP. You would need your cPanel login details to do this, and you may ask your host for these details if you do not have them.
After accessing your site, FileZilla will display your site files and folders on the bottom right. Locate the folder containing your WordPress blog and double click it. If your blog is in your main domain (e.g. blog link is http://www.domainname.com), this folder should be “public_html”. If it is in a subdomain (e.g. blog.domainname.com), then you should see a folder named after the subdomain.

– Search for “wp-content” folder and double click to open it.
– Search for the “themes” folder and double click to open it.
– Next, search for the folder for your currently active theme. Right click on it, select Rename, and change the name of this folder to something like “foldername_disabled” so WordPress can no longer read it.
– Now try accessing your admin panel. If it displays correctly, then there was a problem with your theme. In that case, you may want to delete the theme and reinstall a freshly downloaded copy. If after this, the problem persists, you can contact your theme provider, or change to another theme.

Note: When you manually disable your current theme, your frontend will stop displaying. You would need to activate another theme from your dashboard to fix this issue.
– Now go back to FileZilla and return the folder name to “plugins”.
– Next, go to your WordPress tab and hit refresh on the plugins page. You should now see all your plugins, but they are all deactivated.

Remove empty lines and PHP closing tag (?>) from wp-config file

A good number of WordPress users have reported that an empty line at the bottom of their wp-config file resulted in their WordPress admin panel going blank.
Also, ending the wp-config file with the php closing tag “?>” may cause a similar issue. This action may prompt PHP to send output to the browser prematurely.
To check if any of these are causing your blank admin panel, access your files using Filezilla FTP, and your cPanel login details.You would be able to see your site folders on the bottom right in FileZilla. Double click the folder containing your WordPress files to open it. This folder is usually public_html.

– In this folder, search for the wp-config file. When found, right click on it, select View/Edit, and permit FileZilla to open the file using your local text editor.
– Next, check the file to see if it contains an empty line at the end. If it does, clean it off. Also remove the php closing tag from the end of this file.
– Save the file and allow FileZilla to upload it.

Now try to load your admin panel to see if this solves the problem.

Increase PHP Memory Limit
Sometimes, a blank screen occurs because WordPress runs out of memory. This can happen if your allocated PHP memory is low.
To rule out this error, you need to increase memory allocation to a large enough value, say 256mb. Here’s how to do this:
Access your files using FileZilla FTP, and your cPanel details.
Your site files will be displayed on the bottom right in FileZilla. Double click the directory containing your WordPress files to open it. This folder is usually public_html.
In this folder, search for the wp-config file. When found, right click on it, select View/Edit, and permit FileZilla to open the file using system editor.
Next, add the following code to increase the allocated memory to 256mb (add this code just under “Define WP Debug” – see picture).

define( ‘WP_MEMORY_LIMIT’, ‘256M’ );


Save the changes and allow FileZilla to upload the new file when prompted.
Now try to access your admin panel. If the problem is solved, then it means your issue was due to WordPress running out of memory.

Repair Database
In some cases, a corrupt database could lead to a blank WordPress admin panel. Gladly, your database can be repaired using PhpMyAdmin, and this is quite easy to do.
Note: Before making any changes to your database, we recommend that you back it up first. You can also do this using PhpMyAdmin.

To repair your DB:
Login to your cPanel account.
In the Databases section, click on PhpMyAdmin

Enable Debug Mode
When Debug Mode is enabled, errors preventing WordPress from working normally are displayed onscreen. Because you would not want your readers and customers to see such code errors, this option is disabled by default.
However, these errors can be very helpful when trying to understand what has gone wrong in your site. For example, in the picture below, the error message can help us see why this page is not loading, which is an error in the Pixel-Linear theme.


note: did any body of you encounter such issues!?

Note: i have another wp-site running on the same server - i want to update it to version 5.4 to see if there is the same error on that page too.

i will come back and keep you informed.

- if you have any idea - i love to hear from you !!!



update
': since a second site behaves exactly the same way - i guess that i have to look for the server-conditions.. perhaps i look for this one here Increase PHP Memory Limit Sometimes, a blank screen occurs because WordPress runs out of memory.



i will do so and keep you informed... ;)/>/>/>

This post has been edited by sayhello: 14 April 2020 - 06:00 AM


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Replies To: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

#2 ArtificialSoldier   User is online

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 13 April 2020 - 11:42 AM

Did you enable debug mode?
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#3 sayhello   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 13 April 2020 - 04:33 PM

hello dear Artificalsoldier,


first of all - many thanks for the quick reply - glad to hear from you.


note: i have two sites that are having exactly the same issues:

a. www.job-starter.com
b. www.f-s-j.de


i have the following data on the server:


PHP Version	7.2.27
memory_limit	256M
output_buffering	4096



and both sites ron well in every regard - but one thing does not work at all: the dasboard shows a blank page:


i encounter the issues on both sites: evey time i get a blank page when trying to access the WordPress Admin Panel: http://www.f-s-j.de/wp-admin/index.php

error-code: ERR_EMPTY_RESPONSE

according to this page i do the following to set the debug mode: https://wordpress.or...g-in-wordpress/


define( 'WP_DEBUG_LOG', true );
-or-
define( 'WP_DEBUG_LOG', '/tmp/wp-errors.log' );


i have been turning on WP_DEBUG - but i do not want to suppress the output with WP_DEBUG_DISPLAY?

no: while running with WP_DEBUG enabled i expect issues. so i am very interested to see the kind of output that is causing the problems

the full code i have now in the config-file - according https://wpadvancedad...-with-wp_debug/


define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', true);
@ini_set('display_errors', E_ALL);



see the errorlogs at the bottom of the (main)-page

Notice: ob_end_flush(): failed to send buffer of zlib output compression (1) in /sites/www.f-s-j.de/wp-includes/functions.php on line 4609
Notice: ob_end_flush(): failed to send buffer of zlib output compression (1) in /sites/www.f-s-j.de/wp-includes/functions.php on line 4609



some possible solutions: https://stackoverflo...ompression-1-in

answer 1: WordPress attempts to flush the output buffers on shutdown. It fails because you have already called ob_end_flush(). You should be able to keep compression on, and simply unhook the flush action:

remove_action( 'shutdown', 'wp_ob_end_flush_all', 1 );



You can now call ob_end_flush() manually, and keep zlib compression on.

answer2: It solved when switched off zlib.output_compression in php.ini
zlib.output_compression = Off


and here - also very interesting: https://wordpress.or...nd_flush-error/

Deepak Kumar: Its worked for be by just updating PHP Version to 7+ and set define(‘WP_MEMORY_LIMIT’,’1024M’) in config.php.

rbester: Second one solved by updating PHP.ini (most shared hosting let’s you do that) – memory_limit = 512M.




guess that i have to talk to the serveradmin who cares for the backend of the server.



note: currently - i have the following data on the server:


PHP Version	7.2.27
memory_limit	256M
output_buffering	4096



dear Artificalsoldier i look forard to hear from you again .


regards

This post has been edited by sayhello: 13 April 2020 - 05:19 PM

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#4 ArtificialSoldier   User is online

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 13 April 2020 - 07:06 PM

So it works when you disable output compression?
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#5 sayhello   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 13 April 2020 - 10:05 PM

hello dear ArtificalSoldier,


many thanks for the quick reply. I have not reached the Admin of the server - we will test this within the next 24 h,.


i will keep you informed.

have a great day

regards


update: my serveradmin told me that - after the swith to SSL-on the server so that the pages were delivered with https-protocooll that he encounters many many sigsev.


and he links to some further findings - similar findings that encounter some issues ... https://lists.freebs...ary/115381.html


note: the citated logs are not (!) logs of my server. These logs are encountered on a other server.

PHP 7.2: SIGSEGV in OpenSSL

Quote

Stefan Bethke posted

Mon Jan 21 18:59:04 UTC 2019
Previous message (by thread): which port installed what other port
Next message (by thread): CFT japanese/man on arm and mips
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
I'm seeing a lot of coredumps with a stack trace similar to this, on a 12-stable machine:

# gdb /usr/local/sbin/httpd /httpd.core 
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "amd64-marcel-freebsd"...
Core was generated by `/usr/local/sbin/httpd -DNOHTTPACCEPT'.
Program terminated with signal 11, Segmentation fault.
...
(gdb) bt
#0  openssl_lh_strcasehash (c=0x803466cf2 <Address 0x803466cf2 out of bounds>)
    at /freebsd/checkout/src/12/crypto/openssl/crypto/lhash/lhash.c:361
#1  0x000000080138564d in obj_name_hash (a=0x7fffffffe9d0)
    at /freebsd/checkout/src/12/crypto/openssl/crypto/objects/o_names.c:166
#2  0x000000080143be77 in OPENSSL_LH_delete (lh=0x800a27240, 
    data=0x7fffffffe9d0)
    at /freebsd/checkout/src/12/crypto/openssl/crypto/lhash/lhash.c:302
#3  0x00000008013852c8 in OBJ_NAME_remove (
    name=0x803466cf2 <Address 0x803466cf2 out of bounds>, type=1)
    at obj_lcl.h:12
#4  0x000000080143c15a in OPENSSL_LH_doall (lh=0x800a27240, 
    func=0x8013855c0 <names_lh_free_doall>)
    at /freebsd/checkout/src/12/crypto/openssl/crypto/lhash/lhash.c:198
#5  0x0000000801385558 in OBJ_NAME_cleanup (type=1) at obj_lcl.h:12
#6  0x0000000801392918 in evp_cleanup_int ()
    at /freebsd/checkout/src/12/crypto/openssl/crypto/evp/names.c:83
#7  0x000000080146e39d in OPENSSL_cleanup ()
    at /freebsd/checkout/src/12/crypto/openssl/crypto/init.c:567
#8  0x00000008007a24e5 in __cxa_finalize (dso=0x0)
    at /freebsd/checkout/src/12/lib/libc/stdlib/atexit.c:233
#9  0x00000008007320e1 in exit (status=54947058)
    at /freebsd/checkout/src/12/lib/libc/stdlib/exit.c:62
#10 0x0000000800a55118 in ?? ()
#11 0x00007fffffffeb90 in ?? ()


The one case I could isolate the PHP code is calling stream_socket_enable_crypto(), but I suspect there might be others. Is anybody else seeing this?


end of citation - cf https://lists.freebs...ary/115381.html

note: the citated logs are not (!) logs of my server. These logs are encountered on a other server.
well my serveradmin only points to this finding of stefan bethke. My Serveradmin also encounters the such issues on our server.


ArtificalSoldier - do you think that this is / this could have to do with the topic of the thread the issues with the blank page.

look forward to hear from you+

regards
say

This post has been edited by sayhello: 13 April 2020 - 11:55 PM

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#6 ArtificialSoldier   User is online

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 14 April 2020 - 11:26 AM

I don't know, maybe. It sounds like the person running your server isn't doing a great job of it.
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#7 sayhello   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 14 April 2020 - 11:34 AM

hi there

thanks for the quick reply - were keep on hammering later tonight - and we try to sort out the things.

View PostArtificialSoldier, on 14 April 2020 - 06:26 PM, said:

I don't know, maybe. It sounds like the person running your server isn't doing a great job of it.



well we try to find out what is going wrong - hopefully we get through - we will try out all the things that might go wrong.

Well - this is a terrible annoying error isn īt it . ?!


i come back later the night and keep you informed what goes on here..

;)
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#8 sayhello   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 14 April 2020 - 01:52 PM

hello dear ArtificalSoldier,


first of all - many many thanks for the continued support. Thanks for being here in the thread.


my severaddmin has got a solution - now it is running like a charme
the segmentationfauts are gone now.

but wait: it looks like a workaround:

background:

- but the admin had to recompile on a very very old ssl
- now its running without tls 1.3
- that is old-fashy ssl



note: like Stefan Bethke - here on the freebsd-list has encountered segmentation-faults we also did - we have had such errors also - but now, after the workaround they seem to be gone.

regarding the segmentationfault - in php 7.2 see more here: https://lists.freebs...ary/115381.html

conclusio: i have to look and i guess that there we have to digg deeper - why these segmentation-faults appear!?! and where they are rooted?!


but again: now it runs without any issue - and i can see the admin - page on both pages (both vhosts) that run on the same server.


if i get more insights i keep you informed.


have a great day.

This post has been edited by sayhello: 14 April 2020 - 01:55 PM

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#9 ArtificialSoldier   User is online

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 14 April 2020 - 02:12 PM

That's unfortunate about TLS, you're going to have problems with recent browsers.

Just to check - the server admin is a friend of yours that's learning how to run a server and letting you use it, right? That's not something you're paying for, is it?
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#10 sayhello   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 14 April 2020 - 03:18 PM

no - he is a true expert. do not worry. he has been bugsquashing in the linux kernel for many years - holds a PHD in Computer Sciense and has discussed with Linus Thorvald himself bout the Kernel.


at the moement we are looking and digging deeper. at the moment we look for the openSSL-lib that that is called by PHP and on the other handside from Apache - there is probably a conflict

conclusio: we re on the way - and i am sure that we find a solution... i keep you informed.


and yes: i am glad that you are involved that you stay here and that you support so sustainably

greetings
say

This post has been edited by sayhello: 14 April 2020 - 03:26 PM

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#11 ArtificialSoldier   User is online

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 14 April 2020 - 05:38 PM

This has to be a joke. I have a bachelor's degree in computer science, I have no formal training on server administration, I don't work on the kernel, I've never even been to Finland, and my servers run way better. You keep coming here with problems and it sounds like your server admin is making problems for you. He's the one you should asking about your problems, because he seems to be causing them.
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#12 sayhello   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 15 April 2020 - 10:18 AM

hi there - no joke here sure thing .

now all is fixed...


View PostArtificialSoldier, on 15 April 2020 - 12:38 AM, said:

This has to be a joke. I have a bachelor's degree in computer science, I have no formal training on server administration, I don't work on the kernel, I've never even been to Finland, and my servers run way better. You keep coming here with problems and it sounds like your server admin is making problems for you. He's the one you should asking about your problems, because he seems to be causing them.



guess that doing server work means to be faced with new things every day.

it is sure not like in the gutenberg galaxis where you were able to wait upon changes and discruptive things - 500 or 1000 years _ no - nowadays with the enormous amount of software and tools you can face new things and challenges sooner...


So - i guess that we do not have to discuss in terms of degrees and formal knowledge creating and doing a job while you have learned to do this - in a 4 year traineee or apprenticeship. Today you have to learn faster quicker and so on..

we have had issues with an old openssl lib which was interwinded with old ldap lib - so we have had crashes.

Again - ArtificalSoldier - i really appreciate your help and your support here (and i guess that you allready know this)- but i think that it is surely not necessary to bash the rest of the world - to talk about them in a Donald-Trump-sense like --- ... make something great again and bash the rest of the world for being the newbies that cannot do anything... .
sure thing: - this comparison is not a real one in every sense it is based on a ad-hoc impression ...


Wait, wait, I know what you're thinking - This is comparing apples to oranges - but bare with me for a minute.

In this forum, discussion is encouraged - in Stackoverflow, comments aren't for discussion. You'll get banished to the chat.
In this forum, i allway thougth that i am accepted and i can writeh what is the case - yes i can write (almost) anything ... - in Stackoverflow, your post gets closed as off topic and deleted.
in this forum, human interaction is encouraged - in Stackoverflow, words like "Thanks" and "Good day" in your post are considered as noise.
and yes i allays thogth, every person is considered equal - in Stackoverflow, We're keeping score.
In Dev, we're here to write, read, communicate and share ideas - in Stackoverflow, we're here to solve problems.


I like this forum for the great support and for the fine folks like you ArtificalSoldier (and Martyr and Modi 123 and all the fine Pythonists) are. With idea and knowledge-exchange witout being harsh and.


keep up this great place - it is outstanding - and i really like it!!
and yes ArtificalSoldier -keep up the great work - it is just great!!

have a great day.

greetings

This post has been edited by sayhello: 15 April 2020 - 10:25 AM

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#13 no2pencil   User is offline

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Re: How To Fix A Blank WordPress Admin Panel in Wordpress version 5.4

Posted 15 April 2020 - 01:41 PM

View Postsayhello, on 14 April 2020 - 12:05 AM, said:

update: my serveradmin told me that - after the swith to SSL-on the server so that the pages were delivered with https-protocooll that he encounters many many sigsev.


In your wpconfig.php, are you loading the url with https: ? Also, is there a cert required between the httpd/mysqld? AWS updates their certificates every few years, & this connection can be validated between the command line & the service.

Lastly, the first place to check for white-page errors from php is in your error logs. Looks like you previously mentioned compression issues. What server is this platform using? Apache, Nginx, a combination? Is there a Load balancer involved?

Can you test the site on the localhost? With either curl, wget, or lynx? You can connect at this level to bypass networking issues outside of the server.

Sorry, one more "last". Are there other Wordpress sites hosted here? Do they all experience this issue after the SSL-only switch?
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