Need help to clarify usage of composite model

[QC]

Let me explain the set-up: 

• I published a data model "Base" to a workplace, then gave person A (and only person A) build access 
• Person A: has a composite model, which connects to above PBI Dataset + local data, then publish it to PBI Service (Proxy)
• For Persona A, Proxy is working, however, other users of Proxy (Person B/C..) are receiving an error of "connection couldn not be made to data source", which points directly to "Base" model. Note Person B/C.. don't have access to Base

My question is: do I need to give "read" access of Base to Person B/C? Is that required to use the Proxy (composite) model? 

Thanks,

[lbendlin · Accepted solution]

yes. It gets even weirder.  If you share a report via app (as you should) and the report is based on a composite data model with semantic models from different workspaces then all report users MUST install (register) ALL apps, not just the one housing the report.  Of course they ALL need to have access to do that successfully.