VST issue since reverting to prior version because of issue with latest version

This error: The destination may be full or no longer available kept me from completing some important work, so I figured the answer would be to revert to a prior version. Mistake. All of my settings went bye-bye, and now I'm having the following issue when trying to load up previous multitrack sessions for edit:

Warning: 7 of the 21 effects referenced by the file could not be found: EKramer DR Stereo, Aphex Vintage Exciter Stereo, JJP-Vocals Stereo, RVox Stereo, L1+ Ultramaximizer Stereo, API-550B Stereo, CLA Effects Stereo.

Inside the session's effects rack, I see this:

Is all hope lost, or can one of you help me recover my settings/VST plug-ins for these old sessions?

I appreciate any help you could provide!