More today: I re downloaded both the standalone version and the installer, win32 to be clear. I then uninstalled MyPaint, as well as Krita since I was to install a newer version of that as well. Then I rebooted the computer.
I unzipped and tried to start the standalone version, and got the same error.
I then reinstalled the installer version, same results.
I then tried every combination available in Win8.1's compatibility mode dialog for both MyPaint.exe and Bash.exe. In every case I either got the same error, or no response at all when I tried to start the program.
If it helps: I'm running Win8.1 on a Baytrail tablet w/ wacom digitizer: Asus Vivotab Note 8.
Is anyone else able to run this?