VST2 Plugins reguarly blacklisted in Cubase EL AI 9.5 on Mac OS 10.12

Dear All,

My up-to-date VST2, 64 bit plugins get regaularly blackilsted in my Cubase EL AI 9.5. , on Mac OS 10.12. I cannot reactivate them, cannot find any rescanning option. It would be very sad if this was normal and acceptable.
I would appreciate some advice on this issue.

Thanks a mill and I wish you all the best!
Greg