Final Cut X Pro FilmConvert black screen

Hello all,

I encountered a weird problem in Final Cut X Pro using FilmConvert (plugin). When I add FilmConvert plugin to the video file, the screen turns completely black. Screenshot included below:

The problem appeared while editing video file shot with Panasonic GH4, v-log profile, FullHD, but oddly enough, the problem started to appear with other video files too.

To add to my confusion, Colorista IV, Magic Bulletin (both Film and Looks), Mojo 2, and Renoicer plugins started to add a black bar on top of the screen. The black bar crops about 60 pxls from the top of the screen.

I am unable to complete projects with deadlines, so help would be much appreciated!

I already trashed preferences with Preference Manager, but that didn't help. Also tried restarting both my Mac and Final Cut PRo X.