(I'm assuming you're talking about the offline version of Twine 2, not the online version.) The most common cause of the "white background - won't open" problem is a corrupt "User Data" directory.
To fix this, open Windows Explorer (not to be confused with Internet Explorer), then navigate to "C:\Users\(your user name)\AppData\Local\Twine" and there should be a "User Data" directory there. Rename the "User Data" directory to anything and then try opening Twine again. If that works, then just delete that renamed directory.
If that doesn't work, we're going to need more details, but usually that does the trick.
Also, you don't need to hit the archive button to save, that's all done automatically. The archive button is more for backing everything up elsewhere.
As for Twine locking up, I've had that happen for me when clicking the "Languages" button, after which it corrupted my "User Data" directory. I just don't click that anymore.
Hope that helps! :-)