Do you have any extensions that deal with cookies?

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: "3-bar" menu button/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

I have only 2 extensions. I have disabled the extensions and I still cannot log into outlook after the first initial log in. The default appearance is already selected.

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

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from websites that cause problems:

• Firefox/Tools > Options > Privacy > "Use custom settings for history" > Cookies: "Show Cookies"

I have already cleared the Cache. When I examine the cookies no cookies are stored. The outlook error also reported is 800478A1.

I have cleared everything I could think to clear. the error still occurs.

Only on the second access to Outlook do I get the error message. It asks for my credentials and the error appears. close and open Firefox and I'm able to log in successfully.

I have updated my Firefox version to 44 and the problem can be corrected by clearing the recent history. This did not work in the previous version.