If you're seeing a black screen after adding our plugins to your timeline, most commonly the problem that you've encountered is a result of corrupted font duplicates and/or corrupted font databases – in such situation DaVinci Resolve is simply not showing plugins' contents.
You should see such an error. Below example is about "Inter" font:
Go to mInstaller's Settings and use the [Fix] Fonts option.
If this fails:
Open the Font Book.app (you can find it with CMD+SPACE)
Go to All Fonts
Resolve fonts duplicates via the top menu File>Resolve Duplicate
Uninstall the font in question if you can see it
Empty the trash
Reinstall the plugin with mInstaller
Restart Mac
Open DaVinci Resolve and re-add this title to your timeline