Nextcloud Desktop doesn't work in Windows 11

Nextcloud version (eg, 20.0.5): latest, downloaded from website today
Operating system and version: Windows 11

The issue you are facing:

After setting up server, app began putting temp files in folder, but nothing else. Whenever I try opening the app, I either get to see nothing at all, or the notification popup bottom right of the screen.

All I did was download the app from nextcloud.com, then run the installer again to repair, uninstalled, reinstalled, rebooted, etc.

My laptop runs fine otherwise. I use MS Defender and added nextcloud folder as an exclusion after seeing it didn’t work, but that didn’t help.

I can’t find the log, not a config file under C:\Program Files\Nextcloud.

That’s right, it’s not 1995!

Program Files are for Program Files, not user files. Instead, look under:
C:\users%YourLogin%\AppData\Roaming\Nextcloud

I can see nextcloud.cfg and a log for each share under AppData. Check that out and update your post with anything relevant if you still have trouble going forward.