Hi Denis,

At least now is OK

If on both sites/domains you have the same template and extensions, problem cannot be from SPPB etc. but from PHP settings, and that one is beyond our support.

Sorry, I must have worded it incorrectly. The problem is with the admin panel. The templates are the same, only the domain has changed.

hard to say, reinstall SP Page Builder , clear Joomla cache and recheck. Check also browser in Debug tab (Ctrl+Shift+I) what error you may have

I cleared the entire cache. The error persists.

Share access to Administrator

Создал пользователя

Problem solved. Thank you!

What it was after all? htaccess rule or PHP settings?

Most likely PHP. I installed a previous version of SP Page Builder, and it works. However, all the new posts were merged, and the styles were messed up. I'll have to restore a few posts and adjust the styles.