Have you talked to the schools ISP?

Make sure you are not blocking content.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

One issue that seems more common lately is Firefox's Tracking Protection feature. When it is blocking content in a page, a shield icon will appear at the left end of the address bar next to the padlock icon. This article has more info on managing this feature: Tracking Protection {web link}

See also:

• https://developer.mozilla.org/Integrated_Authentication

• Options/Preferences -> General -> Network Proxy: Settings:

"Do not prompt for authentication if password is saved"

The box is unticked

Alex.luo said

Hello world! I have used firefox to browse at home, but when I try to use the internet at school it doesn't work there isn't a box to ask my for my username and password when I try to use the school network There is a proxy at school that requires a login I have tried to enter the proxy stuff manually but it doesn't work [Use system proxy settings] and [automatically detect proxy settings for this network] doesn't work either Any fix? Anything is helpful! Thanks, Alex

Anything related to a proxy host support should be asked of the school that your trying to login into about the login problems. If they change anything on their site you will be blocked if you don't have login access.