An action hangs while it is actively "Running".
Release : 6.7
Component : CA RELEASE AUTOMATION AGENT
This can happen if the action is configured to run as an alternative user AND:
Another common cause for an action to hang is using a parameter in an action when the parameter hasn't been assigned a value. This scenario is described here: Long running process
There are a few ways to resolve this issue. It depends on how you want to handle using different users.