If, like me, you have been seeing a lot of “Bad Request Error 400” messages or perhaps the yellow bad to the top of Gmail saying “Oops… the system encountered a problem (#400) – Retrying in” then, like me, you will be similarly frustrated.
The details that I outline below aren’t a permanent solution, I suspect that is only in the gift of Google but they will allow you to get back into your email.
These instructions will only work on Google Chrome.
Firstly, from the “Bad Request” page you must do a right mouse click anywhere on the page (see image below) and then choose “Inspect Element” from the pop-up menu.
A new scary looking panel will open at the bottom. Select the Resources tab at the top and then on the left hand side look for “mail.google.com” under the Cookies section.
This will bring up a new list in which you should look for an entry called “GMAIL_IMP”. Right click on this entry and select Delete from the pop-up menu.
You can now close this panel using the cross in the top left of the panel and refresh the page and you should be able to log back in.