It seems the window for creating or modifying search scopes doesn't show the files and directories in the latest Rider version (2023.2.3). I can add a scope but then cannot include or exclude any files or directories from the UI. The selection window is completely empty from the start, and remains so regardless of any changes made in the pattern field.
Entering a pattern manually also seems to always give an error but if I apply the changes, the scope seems to work correctly in the search window.
I enabled the new UI for the first time after upgrading, so it might also be related to that, but disabling the new UI didn't seem to help, so I guess this was broken in the last version in general.
Edit: I use Rider on macOS Sonoma 14.1.1 on an Intel-based Mac.