I usually have long folder names in Windows Explorer, but recently I "fat fingered" some combination of keys and now Windows Explorer limits all my new folder names to 16 characters. What must I do in order to get rid of this limit?
Your question answers itself in a sense.
Since you typically use long folder names in your naming convention I can bet that the path you are attempting to place the new folder in is extensively long.
From the Microsoft Website:
I would venture a guess as to say you are probably very close to that limit right now.