The error occurs when the same dependency is first removed and then re-added. As a result, the follow-up task gets stuck in the "Waiting for predecessor" state for no reason.
The problem occurs in both AE 21.0.9 and AE 24.4.0
Automic Automation 21.0.9 and AE 24.4.0
DE174962
A problem has been fixed, where removing and re-adding a task dependency with the script function MODIFY_TASK (REMOVE_DEPENDENCY and ADD_DEPENDENCY) resulted in the task stuck in "Waiting for predecessor".
Update to a fix version listed below or a newer version if available.
Fix version:
Component(s): Automation Engine
Automation.Engine 24.4.4 - Planned release March 2026