It’s possible to add an action to a recording but forget to add a variable name. Once this happens, the recording won’t run and you’ll receive an error. If you work through the details of the error, should discover what the problem is. Then you need to work through the actions pane to find the offending action.
Is it possible to highlight action that aren’t valid in the actions pane, please? Maybe a yellow highlight or an exclamation mark?
[edit: replaced command + step for action]