Looks like the top bar is not loaded at all on your system. Can you check F12, browser debug, for errors? Also try debug = 2 in application/config/config.php. Thank you.

Are you using a docker image to load LimeSurvey?

Sorry for keeping you waiting.

I'm not using a docker image. I installed Limesurvey from the tar.gz file in the webspace provided by my university according to https://manual.limesurvey.org/Installation_-_LimeSurvey_CE .

Will check for the debug infos you requested tomorrow.

Firefox showed no errors in F12 debug info (though I didn't know what to look for exactly, sorry), also nothing after setting debug to 2 ( I guess I should see any errors displayed onscreen?). A colleague used Chrome on Windows 10, also had no Save- and/or Close-Button as did I when accessing the limesurvey instance with Edge (Win10).
I also deleted the limesurvey instance and emptied the database and did a complete new installation, unfortunately still the same behaviour.

OK, then next step, please do this:

1. Go to the page with the error
2. Click F12
3. Go to the "Network" tab in the debug window
4. Reload the page
5. Check the network tab again and look for any HTML code that is not success, like 404 or 500.
6. If you find any 500, please give us a screenshot of the response of that particular call.

Sorry for getting technical.

Please see the screenshot above for more instructions.

Thank's for the detailed instructions. Unfortunately I found no red marked status entries, all of them are green (200) or transparent (304). I can send the HAR-file if that's of any use?
I'll install Limesurvey on my private webserver too see if there's any difference. I suspect some kind of incompatibility by the university's webspace (although an old Limesurvey 3 instance works flawless).

Thank's for your patience.

If you import a survey, how does the "Edit group" and "Edit question" pages look like? Thank you for the deep trouble-shooting.

Can you please update your LS installation and test again?

Solved in 4.4.0 RC1