I know you think I'm stupid
because I'm not a geek
but does the code work on
any other day of the week?
Does it make any difference what day of the week you run it?
When Problem Solving, you may need to consider timing. Perhaps something failed, due to a time out for example, and that failure affected subsequent processing.
The code was working fine on Tuesday and crashed on Wednesday.
Or is there some other timing issue? Perhaps there’s an increased load on the system?