Mine did the same it was an auto update to 1.14.0
This was my solution
https://community.getmailspring.com/t/help-requested-broken-update-1-14-0-on-win-8-1/8823
Roll back to 1.13.0 and turn off updates as per the advice in this older post
https://community.getmailspring.com/t/database-error-and-unable-to-launch-app-after-installing-v1-10-0/4063/11
hopefully this will buy some time till they come up with an update that doesn’t self destruct!
