Can't create new modules!!!

After installing the latest Version of the pro version I can't create modules in the backend.

Error:
Uninstalling Slideshow CK the creation of new modules works.

It's okay for this project, as I can create the slideshow as llast module. But this will cause big headache on other sites...

JOOMLA! 3.9.8
Ngnix
Php 7.2.18

Regards
Michael

Hi
this is not normal, other people has it working correctly and I don't have this problem by my side
Can you please try again and confirm that you have a success message on install. If you still have the problem, you can just disable the "system plugin - slideshow ck". It shall fix the issue (waiting for the problem to be found)

Then tell me
CEd

I uninstalled all and made a new install - with success message. See screenshot!

Disabling the system plugin I'm able to create new modules.

and you still have the same issue ?
are you using a specific modules manager ?

No, as I wrote:

Disabling the system plugin I'm able to create new modules.

and yes, I'm using Regular Labs advanced module manager - but this didn't affect it. I tried with and without

ok thanks. I will try to reproduce the issue and let you know