This warning message is given by the Divi WordPress theme. Having this theme, when you try to edit one of your posts or pages using the Divi Builder, you might face a popup showing “Divi Builder Timeout” and because of this warning you will be unable to edit your WordPress page or post. This can be very frustrating actually.
Cause of this divi builder timeout warning is that your Divi Builder reached the certain limit which is allocated to the Apache Service which is terminating the process. In order to resolve this issue, we will have to raise the limit and this warning message should not appear again.
To resolve Divi Builder warning issue, you need to add these lines to the .htaccess file of your website:
<IfModule mod_substitute.c>
SubstituteMaxLineLength 10M
</IfModule>
This (.htaccess) file can be easily edited using File manager, Filezilla (FTP Client) or SSH.