An update to a widely used Firefox addon today has broken gmail, tho your in luck the fix is easy.

Normal users using gmail did not run into this problem but people using a particular addon may have been encountering this frustrating error.

The add-on that may have been causing this is Gmail Manager. Gmail Manager adds a little icon to the bottom right of the Firefox window that displays new messages and allows you to manage multiple gmail accounts. This week after they updated to v0.5.7, users began to get an error “redirection limit for this URL exceeded”, when trying to read their mail.

Although this may have frustrating the fix is actually rather simple. All you have to do is update Gmail Manager from v0.5.7 to v0.5.7.1 and that should fix the problem.