I'm getting some error and cannot open my User Preferences window anymore.
I was doing some Python addon development (nothing fancy, just iterating through objects), loading and unloading my addon and at some point I must have killed the User Preferences window. Now when I try to open it by selecting File > User Preferences, a popup displays "Failed to open window!". The console displays:
Win32 Error# (3221692624): <no system message>
I've tried restarting my computer, but that didn't help. I've also tried deleting my script from C:\Users\<user>\AppData\Roaming\Blender Foundation\Blender\2.78\scripts\addons
.
What can I do to restore my User Preferences window?