Affects Version/s: Minecraft 1.12.1
Fix Version/s: None
Environment:Windows (Specifically Windows 10 and/or Windows 7)
Minecraft Literally will NOT run with an appdata path containing an "!" (exclamation point)
My user name for my windows machines is "Thats Bananas!" therefore my appdata directory where .minecraft is placed is: C:\Users\Thats Bananas!\AppData\Roaming
OLD Workaround (now broken):
I Created a batch/cmd script to temporarily change the appdata environment variable to a directory that does NOT contain an exclamation point. Then launch Minecraft.exe with the temp appdata location. and Voila all is good. Minecraft would create a new .minecraft folder into my new location, download the game and run. no problems. The newest launcher does not seem to allow this functionality. It pulls the appdata directory from a different value or somehow overrides my environment variable.
I Purchased Minecraft in April of 2011, this bug has existed since then, but I have always had a work around that was functional. So I never really bothered to enter a bug regarding the !(exclamation point) problem
Prior to the release of your launcher I even had written up my own MC Launcher app in C# that did the same thing, only it worked. I bring this bug to you now because using the latest software I cannot get the .minecraft folder out of C:\Users\Thats Bananas!\AppData\Roaming this problem has rendered minecraft currently unplayable.
I hope that you can either:
1 - Fixed the launcher to properly relocate the .minecraft folder for download and execution
2 - Simply fix what ever exception is hanging up the process because there is an exclamation point in the path.