HI,
I have been dealing with this same issue for many days, since I upgrade the application. I found that I was able to access my notes on all other devices (eg. iphone, ipad, macbook pro and samsung phone. But no matter what I tried on my WIN 10 machine all notes were blank. Also, a blank popup box would appear at times.
Not knowing what would happen, I deleted the application from my machine and reinstalled it from the evernote website:
https://evernote.com/download/?utm_campaign=engt_web_downloadLink_WEB-45641B_v1&utm_source=evernote&utm_medium=web
Once the download and install completed, I am not able to access all notebooks and notes. Here are the app specs from About ...
v 10.4.3 build 0 public
Editor: v112.1.14477
Service: v1.23.6
© 2019 - 2020 Evernote Corporation. All rights reserved
I hope this helps someone.
L