Hello, does Themler 517 and Joomla work with PHP 7.4?

Since 2 week no solution for this problem: I see - for this it gives a lot of thread's. I have made somethings, but no chance. On all my sites, i become this message: Sorry, an error has occurred....

Can't open a template in new migrated website and getting the following reply: {"result":"done","version":"496"}{"message":"\n\nOS: Linux gtwebdesign.protagonist.nl 3.10.0-1062.4.1.el7.x86_64 #1 SMP...