This might not work for your issue, but it’s fixed it for me a fair few times.
Every now and again, I’ll fire up Sublime Text to be met with this:
Usually (as far as I can work out) it’s due to a folder that I was previously working on being deleted/missing and this is causing some issues when it tries to reload the session.
Turning it off then back on again
Rather than do some sort of full reset, you can just delete the session data.
For Sublime Text 3 on Windows, this is located at:
%APPDATA%Sublime Text 3Local
The easiest way to get to that is to hit Windows Key + R, type in the text and hit return.
Inside here, you’ll see the session data.
Try deleting the Auto Save file first (if you have one) and relaunching the app. If it still fails, delete the other session as well.
If Sublime Text still fails to launch, then you might need to do a full reset, but there are plenty of in-depth guides to that elsewhere on the web.