[SOLVED] Changing format for date is not accepted

I am not able to change the Format Date in JEM -> Control -> Settings -> Basic settings  from "D, j. F Y" to "l, j. F Y".
Everytime i safe the old value is being restored.

What version JEM 4.4.4, 4.5.0 RC4 or JEM 5.0.0 RC4?
In my test, it works, but I have forced the filter of these fields to string.

Check this commit:
github.com/jemproject/JEM-Project/commit/d2d865b52743013f410abc0be36c09fa4e67d3f9

Sorry i meant 4.5.0 rc4 but i just see that i can not change anything in the basic settings.
I have to set up my test system. There is something totally wrong.
Sorry.

I cloned my existing system joomla 5.4.6 / jem 4.4.2 with akeba. During restore the only parameter i changed was "enforce ssl for side" to none as i am local.

Then i installed 4.5.0 rc4 from today on top of that installation. Leads to an error. 

 

The update checker says: 
 

There are 3 database errors
 

After trying to fix it - one error left over: 
 

After a complete reboot and trying to edit some basic jem setting I get: 
The most recent request was denied because it had an invalid security token. Please refresh the page and try again.

 

Seems to be now the same issue as in  www.joomlaeventmanager.net/forum/jem-4-x-for-joomla-4-joomla-5-community-support/13119-jem-5-0-0-rc2-_jem_categories-has-the-wrong-type-attributes-column-language#33824
​​​​​​
i will set up the complete test system including database and do the testing with the final release. 

I use now a new ubuntu 24.04 system. The backup from my original system Joomla 5.4.6, Jem 4.4.2 could be installed. 
After installing jem 4.5.0rc4 and fix structure the above error regarding the jem category table still remains. 
I can edit/save everything - events, venues and categories. 

What is the meaning of the error message
Why does the jem database show version 5.0.0 - althouhg jem 4.5.0 is installed?