This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Getting Error: Request failed with status code 404 , attempting to access a route on my dev server

  • 3 cavab
  • 1 has this problem
  • 1 view
  • Last reply by sambient

more options

I have no problem using Chrome , Brave browser to access pages on my dev server. My front end (React) is on localhost 3000, server is localhost 3001. This used to work, just two weeks ago. I'm on FF v95.0.2.

I've tried everything, headers in my index.html, cleared cookies and cache, various network settings, ran it in troubleshooting mode, restarted FF. I have all cors request enable on the server.

Anything I might be missing ?

edit: Found my mistake, had another app opened on the same port , apologies.

I have no problem using Chrome , Brave browser to access pages on my dev server. My front end (React) is on localhost 3000, server is localhost 3001. This used to work, just two weeks ago. I'm on FF v95.0.2. I've tried everything, headers in my index.html, cleared cookies and cache, various network settings, ran it in troubleshooting mode, restarted FF. I have all cors request enable on the server. Anything I might be missing ? '''edit: Found my mistake, had another app opened on the same port , apologies.'''

Modified by sambient

Chosen solution

I know almost nothing about React, so apologies if this is a dumb question, but is a route a URL? If so, does anything look strange in the Network Monitor if you open that tool before loading your page?

https://developer.mozilla.org/docs/Tools/Network_Monitor

Also, just in case, check the Web Console for any unusual messages:

https://developer.mozilla.org/docs/Tools/Web_Console

Read this answer in context 👍 1

All Replies (3)

more options

Seçilmiş Həll

I know almost nothing about React, so apologies if this is a dumb question, but is a route a URL? If so, does anything look strange in the Network Monitor if you open that tool before loading your page?

https://developer.mozilla.org/docs/Tools/Network_Monitor

Also, just in case, check the Web Console for any unusual messages:

https://developer.mozilla.org/docs/Tools/Web_Console

more options

Note that in 95 support for privacy.file_unique_origin is removed (bug 1732052) and security.fileuri.strict_origin_policy will be removed in the future (bug 1730535).

more options

jscher2000 said

I know almost nothing about React, so apologies if this is a dumb question, but is a route a URL? If so, does anything look strange in the Network Monitor if you open that tool before loading your page? https://developer.mozilla.org/docs/Tools/Network_Monitor Also, just in case, check the Web Console for any unusual messages: https://developer.mozilla.org/docs/Tools/Web_Console

Yes, a route is basically a URL. Network monitor looked fine, outside of the 404. The problem was another app was running on the same port and with all the tabs and prompts open I missed it. Usually the app would complain about a port already being taken but for some reason in this case no red flags. Anyway, problem solved.