Diagnosis
No suitable operation/exercise contingents could be found for thehigher-level force element. This can be due to several reasons:
The higher-level force element is neither an operation nor an exercise,nor does it have any relationships to an operation or exercise.
The higher-level force element is an operation/exercise, but all thecontingents of this operation/exercise are in the past, whichmeans that new relationships cannot be created for thiscontingent.
The higher-level force element has operational/exercise relationships,but these are all in the past, which means that newrelationships cannot be created with reference to the contingent.

System Response
Since operational/exercise relationships must always have a reference tocontingents or operational/exercise relationships of the higher-levelforce element, no operational/exercise relationship can be createdin this case between the two force elements selected.