Worker 500 error, but works fine from console

I’m having very similar problems to this fellow here.

When I visit the page of my Cloudflare worker, I see the following:

However, when I click the send button on my worker’s console, I get back the response I was hoping for.

I don’t know why GET requests are failing when sent from anywhere but the console, and there are no error logs to be found as far as I can tell. Any assistance in solving this matter would be greatly appreciated.