Welcome, williamsimms.
This is a known issue that has come about with a breaking change in Glitch, and a fix is in progress. For now, you can try the following:
- Clone the GitHub boilerplate in another platform (CodeSandbox, Repl.it), and complete the challenges there.
- Skip the affected challenges.
My recommendation is that you do not rely on Glitch, going forward, as it has been unstable for the last few weeks.
Hope this helps