Diagnosis
The DataSource was checked for consistency in several source systems:
In the source system for the higher R/3-Release, the InfoObject fieldassignment is incomplete. Compared with the source systems for lowerR/3 releases, the assignment of the specified InfoObject to a field(data element) in the DataSource is missing.

Procedure

Checks and corrections in the BW system (Administrator Workbench:Transfer Rules for InfoSource)
Is it correct and intentional, that the InfoObject assignment for aDataSource field in the source system with a higher R/3 release ismissing?
If the InfoObject is already assigned to the DataSource field, save theInfoSource for the specified source system again and activate it.