RE: Codeunit Page Action doesn't appear in customer client page
As Neil noted, the issue is very likely because the Customer's license does not have permission to read that an object with that granule ID.
This could be a custom object, or an object in an ISV's reserved granule range.
If it's the former, you can check the customer's Manage Custom Object area in PartnerSource to see which custom objects they own, and what can be assigned to them. In the Perpetual Licensing model (NAV 2013 and newer), Microsoft bundles in some custom object ranges with the license at the Starter Pack level, and more with the Extended Pack. Some are pre-numbered, some can be re-numbered.
If it's the latter, you need to either add the ISV's granule to the Customer's license from PartnerSource, or request the ISV to add it to the Customer's license.
In either case, the license must then be re-issued and deployed on the customer's server (and the services, if using NAV 2009 RTC or newer, must be restarted).
I hope this helps. If my response has answered your question, please verify by clicking Yes next to "Did this answer your question?"