Select Tools >  Options

Enabling/Deleting Cookies and Enabling Active Logins

• Select the Privacy Tab
• Select “Use custom settings for history” from the “Firefox will” drop down list
• “Accept Cookies from sites" should be enabled
• Click on Show Cookies
• Click on Remove All Cookies
• Click on Close
• "Clear history when Firefox closes" should be enabled
• Click on Settings
• "Active Logins" should be enabled
• Click on OK

Clear Cache

• Select Advanced and then Network
• Click on the "Clear Now" buttton to clear the cache
• Click on OK

Restart your browser,  to apply the new settings.