406 http code during login to https://www.sandbox.paypal.com/signin

[zoompakty]

I'm not able to login to  https://www.sandbox.paypal.com/signin with any paypal sandbox account I have (even newly created), the 406 HTTP error is constantly returned. Has anyone encountered such an issue, this is a super blocker for me as I can not proceed with Paypal express implementation.
thanks in Advance

[tootalldev]

I have the same issue. Other members of my team can use the same Paypal sandbox account on their machine without issue. But when I try & log-in, it throws a 406. 
Ive noticed it is speratic through. On a call with my lead trying to diagnose it, it suddenly worked again. About 4 hours later, the 406 error re-appeared. 
We use Mac's. I've tried clearing cache, restarting, updating, & swapping browsers.