Salesforce: HTTP Status 400 Error in Chrome

Error

When a user tries to open Salesforce, they are unable to access the application and get an HTTP Status 400 Error in Chrome. 

Solution

Clear Browsing Data

1. In Chrome, at the top right, click the three dots icon (More) > Delete browsing data.
2. Choose Time range > All time, and check Browsing History and Cookies and other site data. 
3. Then, go to All Site Data, search for "force", and clear all the listed results.

Delete Specific Cookies

1. In Chrome, at the top right, click the three dots icon (More) > Delete browsing data.
2. Click Privacy and Security and then Third-party cookies.
3. Click See all site data and permissions.
4. At the top right, search for Salesforce.
5. To the right of the site, click the trash can icon.
6. To confirm, click Delete.

Salesforce also has Recommendations and Requirements for All Browsers (salesforce.com)