Does your internal site use an older version of ssl or a self signed certificate? In the meantime you may need to force Firefox to fallback to TLS 1.0 or otherwise force TLS 1.0 (i.e. set the maximum to 1.0)

In order to change your Firefox Configuration please do the following steps :

1. In the Location bar, type about:config and press Enter. The about:config "This might void your warranty!" warning page may appear.
2. Click I'll be careful, I promise! to continue to the about:config page.
3. Change security.tls.version.fallback-limit = 1

Or you can try an add on that changes the ssl. To be sure that this is the issue, however, check the Web Console for any errors and warnings.

I already tried this. Thanks for answering.

Any warnings in the Browser Console (Firefox/Tools > Web Developer)?

Does the website not load at all or is there a problem when you submit the log in form?

The latter would suggest an issue with cookies.

Clear the cache and remove cookies only from websites that cause problems.

"Clear the Cache":

• Firefox > Preferences > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox > Preferences > Privacy > "Use custom settings for history" > Cookies: "Show Cookies"

Is it that the password does not work, or you keep having to enter it.