What causes "Bad Request" on my browsers?

[Residentx10]

I visit the SAS Authors site a lot to get supplemental material for my book purchases.  

Do you know what causes this? I first got this on Firefox and now I'm on Microsoft Edge and it's starting here too. 

[JosvanderVelden]

It could be caused by too many cookies. If it happens again you can try this if you are using chrome:

Delete specific cookies

1. On your computer, open Chrome.
2. At the top right, click More Settings .
3. Click Privacy and security. Cookies and other site data.
4. Click See all site data and permissions.
5. At the top right, search for the website's name.
6. To the right of the site, click Remove .
7. To confirm, click Clear.