Forge launch fail

[CaptainJala]

Whenever I use forge, even with NO MODS WHATSOEVER, It crashes and says this:

 

" There is a binary discrepency between the expected input class awy (awy) and the actual class. Checksum on disk is b57aca7a, in patch 62d0df8. Things are probably about to go very wrong. Did you put something into the jar file?"

 

I have no idea what this means, please help, I tried the latest and recommended 1.6.4 versions, both with same results.

 

 

[luacs1998]

Re-run vanilla 1.6.4 and re-install forge. This time, USE THE INSTALLER.

[CaptainJala]

First of all, I did use the installer. Second,  I ran 1.6.4 not long ago. But I can try running 1.6.4, though I highly doubt it'll work.

 

EDIT: It worked, weird, but thanks