R12.2.5 - Oracle POET combination

Trying to load the ap invoices with POET information - and it's giving PA_FLEXBUILD error. It clearly indicates it's a project data related error.

How do I narrow down which column /data is causing this issue ?

IS there a way to verify outside the AP interface if the project information we are getting thru interface is valid ?

In general, in PROJECTS , do we have any validation documentation/ noteid that I can refer to verify if the data we are receiving passes thru all the  validation rule?

Thanks,