We are fully browser and ran into this error message a few times and found it was related to the license in use per Session Management for that user. If a user logged into MES which uses a DataCollection license and then logs into the full Office Epicor menu on same computer and tries to open a menu option that requires the Office License (DefaultUser License) then the user gets this message. Possibly the customization has something that is not available on the MES/DataCollect license. To resolve, they had to log out of Epicor MES and log into the Office menu to get the correct license which is visible in Session Management. In our case, there are only a few users that log into both MES and Office so they always use MES from within the main Office menu. The shop uses MES/DataCollection only so not an issue there. This may be a completely different situation but is easy enough to determine.
Glad your issue is resolved! I meant OFFICE MES license vs regular MES license. Our issue was very different and was related to license type being consumed by the user at the time.
If not, your users will sometimes get the customization, and sometimes not. Without the override there are two events that fire, and it was random for us which one loaded until we switched to override.
