Making Client Unusable

So i was wondering could i make an old client unusable, but still use the same ip?

if yes, then how might that be.

You stupid. You change the build version in the client and the server so that the server only accepts clients with the updated build version. Basic RotMG shit right here.

Oh ya i'm so ******* stupid

but could you tell me the file location i forgot where it was located'
@059 @Ahlwong @Raple Close Lol Sometimes My Brain Doesn't Work