Keychain Error Logging into OneDrive on Mac

I keep getting an error message when trying to log into OneDrive on my Mac.

It says..."There was a problem accessing your keychain. Please check that the login keychain exists and that OneDrive has access to it."

I have previously had my files on my computer and still do, but they are not syncing, and clearly the reason is that I am not logged into OneDrive anymore, but I can't figure out how to get back "online". FYI, my username and password are NOT the problem. 

Please advise??