I’m sorry you had to deal with that! I put this script together quickly, and I wasn’t particularly careful about handling exceptions. I haven’t had time in the past few days to work on an updated script, but the plan is to use what I learned here to put together a better-thought-out/more stable/more robust ‘magic templates’ script in the next week or so.
In the meantime, the script shouldn’t run into problems so long as everything it ‘expects’ to be there is there. (The theme shouldn’t be affecting anything.) So that means: A ‘Today’ project, a ‘Schedule Templates’ project, events for the day. If those are all there, the script should know what to do. (The updated script won’t crash when it can’t find what it’s looking for.)