Installed - set up backup - but absolutely nothing happens

The destination I set is full of files: 1,814 files, each one around 102,379 KB.
All files end with dindex.zip.
Live log shows:
Aug 29, 2024 3:54 PM: Failed to load assembly C:\Program Files\Duplicati 2\Xamarin.Mac.dll, error message: Non-abstract, non-.cctor method in an interface.

this is a mess…