1st we create a multilanguage page (de/en), than we deactivated this, and come back one language only. After last Update the themler for Joomla 3.x.x we can't open themler now We get an ERROR. So we...

I have problems with some parts of of my designs made with Themler after upgrading from PHP 7.4 to PHP 8.0. The warning is the same, but it appears in different place on different servers. Here is...