VST Presets are not saving

Cubase 9.0.1 / Mac OS 10.11.6

Can’t save preset for Groove Agent, or any other third-party VST:

Clicking Save Preset in context menu - window is showing up with no presets there -> enter preset name -> pressing OK is doing nothing - preset is not saved. New Folder button is also doing nothing.

I looked through the forum - tried to delete preference files - did not help, Veryfying and fixing File permissions as adviced also did not help.

did you select the directory & rescan in Mediabay?

here’s a work-through that works for me:
1- save new preset with unique name
2- do a system search for that name (eg. in explorer for Windows)
3- when you find that directory then go to Mediabay and find that directory, select it, rescan

I found my solution. It happened only on VST3 plugins. I had to turn off the “hidden” status of subfolders and files under Documents/VST3 Presets.