Plugin causing whitespace after admin login

Hi @juppi91!

Thanks for reaching out.

I’m having trouble loading your site, it is just returning a 500 server error. Have you been seeing this error lately?

I appreciate that you have already tried some troubleshooting! I’m unable to replicate this on any of my installs — event with the Tempera theme. Are there any other plugins on these WP installs? If so, can you take a run through our testing for conflicts guide?

If that doesn’t reveal anything, I would look into the cause of the 500 server error.

Take care,
Ed ??

Hey Ed,

thanks for your reply. Until now I have not encountered any 500 server error when loading the page (index.php).

I am running my installations with several plugin and did a run through your guide and found the following issues:

Two of the plugins (Enhanced Media Library and Simple Comment Editing) are causing whitespace but only in tempera theme and not in twenty fifteen so I suppose it has nothing to do with TEC.

Two other plugins (Mail Poet 2 and Smart Slider 3) are causing the whitespace regardless of the theme (even with twenty fifteen) on two different installations. One the one with Mail Poet 2 TEC is not the latest version and on the other it is the slider plugin whereas TEC is up to date.

I tried updating the plugins and got a 500 internal server error. The request url is hinting to the admin-ajax.php. After deactivating TEC again the Smart Slider update was successful but still the admin area wont work if I activate TEC and Smart Slider together.

For the installation with the old TEC and Mail Poet 2 I have to run further checks to find out which plugin is causing an error when I try to update TCE.

Probably you have more indication to help me finding a solution.

I’m able to load the site now, it looks good as far as any JavaScript errors or anything is concerned.

It’s pretty tricky when plugins don’t want to get a long. I’ll install some of those and see if I can come up with anything further.

I do have a feeling that once updated, you should see less conflicts happening there. Could you try manually updating the plugins that need it — I would definitely perform a backup beforehand just in case something does go wrong, but for the most part plugins store their info in the WP database, not actually in the plugin files.

Take care,
Ed ??

Hey Ed,

on our testing page at https://www.blowboys.de/neu/ I did all available updates now.
I deactivated password protection for the moment so that you can view the frontend. Unfortunately activating TEC and Smart Slider 3 at the same time leads to a 500 internal server error after logging in to the admin panel. I left the page with both plugins active for the moment.

Could the problem be caused by a partly wrong configuration of the htaccess or the wp-config.php regarding https-rules?

I left our official page as it is for the moment as I don’t want to mess it up (www.blowboys.de).

Thanks for your help!
Felix

I’m wondering if the combination of the two plugins are just pulling too much memory. You can try to increase the WP memory limit with this line in wp-config.php:

define('WP_MEMORY_LIMIT', '128M');

As for .htaccess, many times 500 errors will be attributed to them, but I don’t believe that Smart Slider needs and rewrite rules. Unless you have recently changed your .htaccess, I doubt that it’s the culprit.

Give that a shot!

Thanks for the tip. I increased the limit to 128M and even tried with 256M on the testing page. Unfortunately this does not change anything. I further enabled the debugging mode and got the following reading:

Notice: Constant WP_MEMORY_LIMIT already defined in /…/neu/wp-config.php on line 124

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 38000 bytes) in /…/neu/wp-includes/functions.php on line 351

I deactivated Contact Form 7 for the debugging because this lead to several warnings and did not reveal the fatal error.

Line 124 is exactly the place where I defined the memory limit. Obviously the problem seems to be caused by a memory problem. Line 351 of the config is part of the is_serialized() core function but I don’t now wether this affects the memory.

Regarding the .htaccess I must admit that a made changes some weeks ago when switching from http to https but the page admin area worked just fine for the time till this error.

The .htaccess has the following configuration:

# BEGIN WordPress

RewriteEngine On
RewriteCond %{SERVER_PORT} !=443
RewriteRule ^(.*)$ https://www.blowboys.de/neu/$1 [R=301,L]
ErrorDocument 401 https://www.prochnow.eu/err401.htm
ErrorDocument 404 https://www.prochnow.eu/err404.htm
ErrorDocument 403 https://www.prochnow.eu/err403.htm
ErrorDocument 500 https://www.prochnow.eu/err500.htm

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /neu/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /neu/index.php [L]
</IfModule>

# END WordPress

As there have been some new plugin and core updates I did a nother updating but still without any change. This seems to be a tricky thing …

I played around with the plugins you noted as well as the Tempura theme and could not get my test install to break — even with limiting the memory limit.

One other thing I can think of would be to refresh your permalinks, .htaccess looks normal. Another idea would be to try a fresh version of Tempura without child and see if this is causing troubles.

This doesn’t seem to be an issue with The Events Calendar or even a conflict.

Hope that helps!

Thanks for the hints and your help.

I refreshed the permalinks and testest whether a change to tempera without child theme changes anything. Unfortunately it does not and even with twenty fifteen theme the admin area returns an error 500 with the whitespace.

Although I am using a bunch of plugins the admin area only crashes when Smart Slider an TEC are active at the same time. If one plugin is active without the other the admin area seems to work fine.

Hi @juppi91 and @erishel

I’m Ramona from Nextend, we’re the developers behind Smart Slider 3.

I also installed Smart Slider 3 and The Event Calendar on two of my tests sites and they worked fine nicely beside each other. Are you using the Free or Pro version of Smart Slider 3? Are you using the latest version? I did try both, so that shouldn’t actually matter.

Do you possibly have access to your server’s error log? Maybe it would worth a try checking if that says something about the problem.

Hey,

thanks for your help so far.

I am using the free version of Smart Slider 3. All plugins and the wordpress core are updated to the latest version.

I checked the error log today and found a notice about two lines in the .htaccess beeing ignored. As those lines just lead to error documents and are not necessary I took them out for the moment. Unfortunately that does not change anything except for the fact that the error log is now empty.

I still wonder why the problem only occurs with both plugins active at this installation. As I have similar problems on my other wordpress installations I run with https I started a support request to the web hoster to check whether there is a general configuration error.

Hi @juppi91!

If the memory_limit on your server is reached, probably the connection to our two plugins are, that they are both bigger plugins requiring a certain amount of memory. Also if there are many plugins you have, that ~67M memory could be easily reached and servers usually don’t give access to users to increase the memory_limit from the PHP code and your tests might have still happened with the lower memory_limit.
You should ask your server host to increase the memory_limit to 128M and take a look at the problem like that!

If this won’t help and your host won’t be able to help either, write an email to us to [email protected] and we will help to figure out the problem!

Thanks for the hint.

I did a test with the server configuration outside from wordpress. My hoster offers a kind of php error switch. Unfortunately there is no indication what the switch does precisely. I would expect that this is just another kind of error log. I enabled the switch just for testing and was able to see that the memory_limit is set to 192 mb in the server menu. After activating the switch all my affected wordpress installations seemed to work fine. I do not know why, but after disabling the switch again and trying to login to the page(s) everything still worked. In both settings the health check plugin read a wp_memory_limit of 256M.
On the one hand I am happy that everything now seems to work, on the other hand I am not fully satisfied as I have now clue about the cause of the error.

I will check whether the wordpress installations work properly for the next days and hope that the issue will not reoccur.

Thank you all for your support @erishel, @nextend_ramona and @nextendweb_gabor!

Awesome! Glad you got it figured out for now.

I’m going to go ahead and close out this thread — don’t hesitate to create a new one any time you need help!

Take care,
Ed ??