JohnO'Mullane:
It seems, Automic introduced a restriction of rekursion in the latest versions 12.1.x and 12.0.x (in our case 12.0.4). Maximum depth seems to be 16 iterations.
We've encountered this issue right after upgrading from 12.0.3 to 12.0.4 because some scripts and jobs failed. Even some JOBFs with ACTIVATE_UC_OBJECT in PostProcess getting this error message.
Maybe you can refer to this problem:
PRB00219857
A Workflow activating an external Script which activates the Workflow again stops after 5 runs