If you are receiving the message "Error 500 - Internal Server Error"
while attempting to log in using Mozilla Firefox, you will need to follow the steps set out below to resolve the issue.
You will need to clear the cookies in Firefox.
Alternatively, it's right click on the page, then click on "View Page Info" in menu, then select "Security" tab, see attached screenshot
Attempt to log in again once you have cleared the cookies.
If the above actions have not resolved the issue, please contact firstname.lastname@example.org and one of our agents will help you out.