Blender input and shortcuts error This error just happened. I can't rotate my viewport using mmd. I have reinstalled it but nothing changed. Not only mmd, I also found that when I press S, the "insert keyframe" menu showed up. It must be shows up when we press I, right? Not obly S, but I also found errors on another, like A, Z, and much more. Can anyone fix my problem?
Just go to File menu in blender > Defaults > Load Factory Settings
This Can Work For You But if This Does Not Works then I have Another Idea for you if you are having windows operating system
you should uninstall blender first then before reinstalling it you should go to your c drive or the drive where your operating system is installed then let us suppose it is in C drive so try searching for blender in your file explorer in the c drive 
now delete all the file relating to blender except your project files
also you should go to c drive > program files > Blender Foundation 


  Delete this folder (Blender Fondation)
  now there should not any system file related to blender and then you should re-install it again
  hope this will work !