Mozilla Firefox users are prompted for credentials when attempting to log-in to Microsoft Dynamics CRM 2011 using Windows integrated authentication.
This behavior is by design, as Firefox rejects all SPNEGO login challenges (Kerberos, NTLM, or other authentication protocols). For more information regarding this behavior, please see the following article:
This issue can be resolved by altering the network.automatic-ntlm-auth.trusted-uris configuration property to include the Microsoft Dynamics CRM website.
In Firefox, navigate to the following URL: "about:config".
If a warning page appears with the message, "This might void your warranty!", click "I'll be careful, I promise!".
Locate and double-click on the network.automatic-ntlm-auth.trusted-uris string property.
In the "Enter String Value" box, enter the URL address used to access the Microsoft Dynamics CRM website (ex. http://crm). Please note that multiple websites can be separated in the string value by using a comma.
Close and re-open Firefox.
Cross browser compatibility was introduced to Microsoft Dynamics CRM 2011 in Update Rollup 12. Previous versions of Microsoft Dynamics CRM are not supported for cross browser access.