There is a typo in the original text.. it should be "pcbAppOBJ" not "pcbAppOBU", but the question is still valid. That typo is not the problem.
You should request a license from automation license server when you want to access PCB document.
Please refer to "Using Automation Licenses and Document Validation" section in PCB Automation Reference(expedition_pcb_auto.pdf) delivered with the software installation.
If you have access to supportnet, you can simply check the below page.
Hope this helps,