At present I am running 10.75, but up until yesterday I was running whatever the prior version was. They probably sent me some emails telling me I need to upgrade, but I don't recall seeing them or they went into my spam, etc.
I was able to locate what I believe is my old versions database, or at least a folder in the root of my profile folder call Evernote that has a database last modified yesterday morning around the time I got logged out of the old version, and a bunch of cache files that have date modified that go backwards day by day from there. Problem is, I cannot get logged back into my account using the old version. The old version seems to be blocked. So even if I copy all that data over to another computer and install the previous version, I cannot get logged in to view my data, so what can I do? I think I need someone from Evernote support to assist here and I don't know if that is even a possibility. Going to guess that my previous version was v9.x, but I don't have access to know for sure.