GuestUser-1.2 shut down my site with an error message

My site shut down after I extracted the 4th out of 5 plugins, GuestUser-1.2, into the /plugins folder. Every page now says “Omeka has encountered an error.” I was trying to upgrade GuestUser, and I don’t have a copy of the old version. Needing a quick rescue!

Omeka Classic Version 3.1
Emiglio Theme 2.4.2

I just extracted the 5th plugin upgrade, UserProfiles-1.3. My site worked again! Then I went back to my Plugins page and clicked Upgrade on UserProfiles. My site crashed.

I solved this by deleting UserProfiles in my /plugins folder. When my site came back, I clicked upgrade on GuestUser. Then I reinstalled and upgraded UserProfiles. It works!