Hi Everyone,
I am very sorry for the inconvenience this is bringing to all of you! I am trying to resolve this as soon as possible. Thanks a lot @Predeactor for the great workaround described.
I will document any progress regarding a the development of a solution here: https://github.com/Foundry376/Mailspring/issues/2373
I hope that I can find a solution fast in order to cut a bugfix release for this.
I hope this is the right catalyst to implement a switch in settings to let the user update when they want to. I’ve opened issues on that in the past but the developer is way too opinionated for his own good. Not the first time mailspring mucks up after an update, you’d think by now the decision to make updates optional would have been made.
Might want to append the guide to rename update.exe because it auto updates the next time mailspring.exe is launched (user quit, logout, reboot, crash, whatever).
[ Solved ]*******
This is how you can survive this 1.10 update. btw noob here.
uninstall mailspring.
–Edit : as noted by @predeactor skip this step and try if you do not want to lose your settings and data (delete the items inside this folder
C:\Users\XXXX\AppData\Local\Mailspring )–
{XXXX- Username}
download the Mailspring v.1.9.2 here : https://github.com/Foundry376/Mailspring/releases/download/1.9.2/MailspringSetup.exe
and install the same.
open and sign up and add just 1 account.
close the Mailspring app in the Task Manager to shut it completely.
go to C:\Users\XXXX\AppData\Local\Mailspring
Find the file “Update.exe”
rename the file into “Update.exe.old”
go to this folder
C:\Users\XXXX\AppData\Local\Mailspring\app-1.9.2
find and right click on the file “mailspring.exe” and Click " Send to - Desktop (create Shortcut)"
come to desktop and find the “mailspring - Shortcut”.
Use only that shortcut file to open the Mailspring from hereafter.
If error occurs repeat from step one.
Hope this Helps!
Done, thank for pointing this out, hope it won’t break the app!
Your solution erase user’s data, settings, etc… This is not a good thing. My guide does not do that and my guide cover most of what you’ve written already without any user’s data deletion.
Just wanted to let you know. Maybe you could consider pointing your guide to mine too 
Could you kindly link to this guide that does not break the app? Please and thank you 
Here you go, Database Error and unable to launch app after installing V1.10.0 - #11 by Predeactor
Hope the best for your fix!
This seems to have worked, thank you! Is Mailspring working on a fix for this? Where would we check for communications from them regarding it? Any chance you know?
I’ve been emailing Ben (One of the author) about this issue, he answered me by telling me they’re working on it ASAP!
There also is this post made by Phylu, so you can check the progress here!
Hello, thanks a lot you solve my day, I only registered to thank you for the temporary solution. I have always used Mailspring as my mail app, so it was a great workaround until the next update fix it.
Greetings.
Ayy! Thank for the kind words, it’s very appreciated!
Made an account just to jump in and say thank you for this fix/workaround. I really appreciate it.
That is all.
thanks for temporary solution, apparently it worked for me
Thank u for taking time to share this fix, greetings!
Thanks for the effort, keep it going
Hey buddy. @Predeactor Do you have any solution for this sync error?
I have subscribed to mailspring but i could not find any solution for this error. It is really frustrating. I would really appreciate if you could help on this one? i could not able to reach the support team as well. Please help. kindly point me to the right direction if you can…