Part Not Confirmed

I work at a distribution center that uses SAP.  I get complaints from my inspectors that they often get a message from the system indicating "part not confirmed", when they are trying to process a part through inspection.  The team leaders do something to override this message and continue processing the part, but this issue detracts from productivity.  Can you tell me what causes this issue and what I can do to eliminate the problem?

Thanks,

Don W.