I installed 21.08.3, the latest version available in the Kubuntu software centre. The previous version was not uninstalled so I don't know if that's a problem.

Whenever I try to render a video, it gets stuck on "waiting ...". I noticed there's a start job button now, so I clicked on that but it's still doing nothing, even after waiting 8 minutes for something that used to take 2 minutes.

I looked around on the internet and this seems to be a frequent symptom, but everyone's solution seems to be different. I've tried uninstalling and reinstalling (but it still left the old version there), I've tried changing output format, I've tried clicking the "Bypass codec verification" option, all solutions that have worked for different people in the past, but no luck with me.

Did you try the appimage?

No, I've never used it. How do I get one for kdenlive?

I managed to find and download the appimage. it's less convenient to use but at least it renders.

unfortunately it doesn't solve the other problem i posted about on the other thread. i'll put a message there.