99% of the time, "bad request" errors on a browser can be solved by clearing cookies/cache. Clearing the cache folder may log you out of some websites or extensions. Caching is intended to help the website load faster, but it might also cause issues if there are too many files stored in the browser’s cache folder. It is an important first step in resolving issues related to internet browsing. 

If you are unsure how to clear your browser’ cache and cookies, see Clear Your Browser Cookies, Cache, and History.