I have a bunch of those errors throughout my log. It's probably not your issue, however @peternlewis can give us the final word.
However, to be sure, you could add this to the beginning of each macro involved in your sequence:
This will put messages in the log file, which could help you track down where the error is. You might have to add more log messages inside a macro or two to narrow it down to the exact action, but it's a start.