Me neither but I guess it is a problem with the new hotfix. I'm going to try with (hexed/spoofed) 123.5.0
EDIT:
I've done it super fast with spoofed 123.5.0 at first try O.o
Get a hacked 123.5.0 client and open it with Notepad++ (yeah, who cares Yogda?), press CTRL+H enter 123.5.0 to search and 123.5.1 to replace and save.
Done!