When you get a 500 error, the first thing to check is if it's on a single page, or the entire site.

If the entire site, then, via the terminal, run python __init__.py, and then you will see the error in the script. If it's a single page, encase that entire page in try/except, where the except returns the str(e) of the error. Fairly certain that was covered in the course, but then you can see the error and fix it accordingly.