I am not sure if i understood you corectly, but - if you have changed domain you probably locked yourself out from NPrinting. Is NPrinting service still running? Can you RDP to NPrinitng server and check it?
After domain change i would thought they will not run properly!
If services are running You should still be able to login using NPrinintg login (using email address used during the setup of environment)
Domain change has a big impact on NPrinitng environment therefore i would suggest you contact support or your Qlik partner to get it fixed. I don't think this can be properly resolved via community.
cheers Lech, When applicable please mark the correct/appropriate replies as "solution" (you can mark up to 3 "solutions". Please LIKE threads if the provided solution is helpful to the problem.