An action to set a variable causes a coercion error:
So the action is disabled in the workflow editor and the workflow republished.
The coercion error continues until the disabled action is completely removed from the workflow.
Why is a disabled action throwing an error at runtime?
Are you sure the workflow wasn't running prior to your republish where it was disabled? Any workflows in progress at the time of publish use the old workflow logic opposed to the new logic. Just a thought.