You may have some bad IDs in your AdjointCatchment feature class. The delineation tool performs first a local delineation within the catchment associated to your input point and merges the resulting shape with the associated AdjointCatchment feature. Rerun the AdjointCatchment Processing tool to regenerate the AdjointCatchment feature class. This should fix your issue.
Christine Dartiguenave
Esri Water Resources Team