“There has been a critical error on this website” when editing any post

Hello @larrydaniele and thanks for reaching out to us!

PHP Fatal error: Allowed memory size usually occurs when your site has exhausted all of its memory, which would be a performance issue.

Are you using any sort of plugin for editing your pages? If deactivating Wordfence seems to resolve the issue, we could try Learning Mode to see if the WAF is blocking by mistake.

From the Wordfence Dashboard click on Manage WAF. Then you will see Basic Firewall Options > Web Application Firewall Status. Change the option to Learning Mode. Now perform the actions that were causing issues. This will help Wordfence learn that these actions are normal and it will allow them in the future. After you have finished performing the actions, switch the WAF from Learning Mode back to Enabled and Protecting. Now test to see if these actions work correctly.

https://www.wordfence.com/help/firewall/learning-mode/ is an amazing resource for learning more about the WAF and learning mode.

Let’s start here and see what we get.

Thanks!

Hi @wfadam. Thanks for your help with this.

We are using the Avada theme with its Avada Builder page editor. But the post I’m primarily testing is using the WordPress “classic” editor (not Avada Builder nor Gutenberg / Block editor).

I activated (and verified) Wordfence Learning Mode. I then tried editing this post and once again get the “white screen of death”. In debug.log is:

[28-Jan-2021 14:12:43 UTC] PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 131072 bytes) in /home/ghfzv6awifsr/public_html/wp-content/plugins/wordfence/vendor/wordfence/wf-waf/src/lib/storage/file.php on line 618

And editing the post with Wordfence disabled works fine.

• This reply was modified 3 years, 10 months ago by Larry Daniele. Reason: Added additional information

Can you send a diagnostic report to wftest @ wordfence . com? You can find the link to do so at the top of the Wordfence Tools > Diagnostics page. Then click on “Send Report by Email”. Please add your forum username where indicated and respond here after you have sent it.

I want to see if I can tell what might be tipping the scale on your performance. I think what is happening is the memory is exhausted and when you disable Wordfence, it’s clearing just enough RAM to run the editor.

Thanks again!

Diagnostic report sent.

Thanks for sending that diagnostic!

I don’t see anything there that might be causing an issue. It might be best to get a performance report from your host unless you have access to one.

Any way you can send us raw access logs to see what might be triggering it? If you have the WP Debug, that would help as well! Just send them to wftest @ wordfence . com with subject as your forum username.

Thanks!