It has nothing to do with Anti-GM.
Go to:
Character --> C_IP_PERMIT
By default there is only 1 line there and in column valid_string it has:
Code:
[GM],[DEV],[DEKARON],[OPR]
Change that to:
Code:
[GM],[DEV],[DEKARON],[OPR],[VGM],[MOD]
And that will enable [VGM] and [MOD] tags in the database.
Also... If you know how to make queries, you can actually restrict which IP can use a GM character in-game with that table, and I'm making that in Anti-GM-hack v3...