I tried the installer I had - it installed ok, but it would not let me 'login' because it didn't have an internet connection 😒 That's the sort of fragility I've struck before.
So, I downloaded and installed the 'legacy' version. Pleased to report that it has given me access to my data. Now at least I can look for an alternative that can read exported data.
Local notebook support is the main reason I have stuck with Evernote. At one stage I was considering a switch to OneNote, but then MS did the same thing, forced everything into it's cloud.
The main reasons I have a BASIC account are:
My primary use of EN is to store 'free format' data that is arbitrarily linked to and from local 'databases' that I access and maintain with other applications.
I don't have an 'always on' 24*7*365 internet connection, which is why I want all my data local;
I have never found a usage case for any of the Premium advanced features;
I don't need extra online storage or traffic;
If there was an account type that allowed users to have local notebooks at a modest cost I would subscribe in the blink of an eye. Example: I subscribe to MS Office 365, but I don't put my documents into MS OneDrive. Not even for backup purposes, I prefer to stick with the commercial FTP service I've used for the past 30+ years.