Since your Evernote data are in an Evernote account hosted by Evernote, independent of your computer, I would think that installing a clean version of Evernote on your computer and logging in with your previous Evernote ID would restore everything you had with Evernote, regardless of what happened in-between.
You would think, but there are lots of other factors in that story.
Whether the Notebooks and their enclosed notes and documents are
Synchronized on the Evernote servers or they are
Local on your computer is
optional. You can have both. If you have a lot of notes you can quickly fill any free disk allocation for
Synchronized Notebooks and have to get a Premium Account (a.k.a. spend
$$).
I was caught by the same update Kate referred to and the problem was a bad release from Evernote and had nothing to do with Apple or the App Store other than their being a distributor. That update broke several things in Evernote but
the data was never actually lost. The problem was Evernote would take anywhere from five to thirty minutes to open a note and display it.
Like Kate, I initially assumed the database was lost but I found out on Evernote's own discussion boards what was going on. Their Tech Support at the time was apparently ducking for cover from all the incoming flack they were getting.
It took Evernote two or three rapid fire updates before the data would once again load normally and at least one more to restore full functionality. During that interregnum Evernote was so busy "fixing" problems they did not release the updates to the App Store, but distributed them online from their own servers. To be truthful I am not sure when the App Store and Evernote releases got back in synch but the current App Store version is Evernote 6.0.13 and came out in late May.
If Kate still has the original Evernote data files, or if her
Notebooks were synchronized the files are still there and should be recoverable by the simple expedient of downloading the latest version of Evernote from the App Store and logging on to her Evernote account. It should still be there and accessible. Once Evernote got things sorted it has been very stable and I find I am using it for more and more things. In fact I am finding more and more iOS apps that talk to Evernote and expand its usefulness.
