SYMPTOM:
The following error occurs when attempting to run a report from Strategy Web 9.x and 10.x:

SQLEngine got an Exception from DFC: Engine Logic: Insufficient privileges: can not execute a report that uses multiple data sourceError in Process method of Component: SQLEngineServer, Project #####, Job 9718, Error Code= -2147212800.)

Refer to the following KB for related causes of the above error:
KB32672: "[DFCENGINE] Engine Logic: Insufficient privileges: can not execute a report that uses multiple data sources" error message appears when running a multisource report in MicroStrategy Desktop 9.x