Specific user having issues accessing

We have 200+ users with access to an existing folder, and we are not close to reaching the collaboration limit (so that's not the issue). One user specifically cannot access the folder and is receiving error messages every time he attempts to access the link (screenshot attached). The error states (403. That's an error. Your client does not have permission to get URL". We have removed and readded two different emails associated with this individual numerous times but that does not seem to work. Every user except for him has been able to access - what are the work arounds? Is it an end-user issue? Something in their web settings?