Zotero cannot update and the program closes

I recently tried to roll back from the Zotero 6 beta to Zotero 5 for continued PDF annotation functionality. However, now I cannot use the program at all.

When I open it, I get a message saying "This database requires Zotero 5.9.97-beta.55+3b993b2af or later" and an option to check for updates. When I check for updates, it says none are available. Then I click ok and the program just closes.

How can I install a working version of Zotero? Why does the new Zotero 6 not work with MDnotes and Zotfile?
This discussion has been closed.