Why am i seeing the error message , for i am the law andi am the lash

[Zenithing-daggerspine]

i am trying to use the cudgel for the quest and , i get this error message, that i cant use that item yet?

[Nok-winterhoof (Nok)]

Take the disguise off and reapply it.
ISTRC that you get that message once you have been discovered.

If your disguise is gone, you can get another one at the table.