I'm working on pset7, register and I'm at a loss for how to fix this issue. I'm fairly certain my application.py logic is correct because once the form finally submits everything works as expected. I also don't think it's my HTML, because the login page as implemented by the staff is doing this too.

I tried putting a print() statement at the top of the register() function; and when the page first loads, it prints to the command line and the page displays. I fill in the form and submit, the print statement doesn't execute, and I get this in chrome:

This page isn’t working ide50-allclay1993.cs50.io didn’t send any data. ERR_EMPTY_RESPONSE

If I open dev tools, I see that the request fails, and there's no Request Method header. Then if I keep refreshing it eventually works. What else should I look at?

  • Since login gives the same result, I would suspect something in the browser:settings, add-ons, cache? Have you tried ctrl-F5 refresh (clears cache)? Have you tried another browser? Or "safe-mode" (firefox lingo, add-ons disabled)? Jul 24, 2018 at 19:15
  • I didn't think to check those things, I just tried all of that in chrome, and still have the same issue. Installing firefox now. Jul 24, 2018 at 19:48
  • It works more often in ff, but the issue still happens sometimes. However ff says "The connection to the server was reset while the page was loading." Jul 24, 2018 at 20:20
  • Those two messages (ERR_EMPTY_RESPONSE and "...connection..reset") converge at http/https. And that heads down the rabbit hole of anti-virus, proxy, firewall. You might have to seriously parse through the network data in dev tools to find the difference between when it works and when it doesn't. I cannot make sense of the fact that repeated refresh eventually works. (Flaky internet cnxn?). Sorry, I've got nothin'. Jul 24, 2018 at 22:15
  • Thank You! I turned off my antimalware and firewall and it works perfectly now. Jul 24, 2018 at 23:29

1 Answer 1


To others with this issue: If all else fails, turning off your antivirus/malware and firewall may be the solution. Just don't forget to turn them back on afterwards!

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