That is a new one on me. Unless someone has seen that I would suggest making a copy of your Maya folder in the your Documents folder and delete the original then start Maya again. That will recreate the default prefs folder in the event you accidentally got something corrupted.
DO NOT delete the original maya folder before making a copy or simply renaming it. If there is nothing wrong you can restore your version in case you have made cchanges to prefs you do not want to lose
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675