I seem to be having the same issue that is located in this thread https://community.office365.com/en-us/f/172/t/236885 but it is already archived so I cannot post in it. Nothing posted there has answered my question or solved my problem.
There is nowhere for me to enter any credentials to fix my sync error. Instead of the "Enter Credentials" button I have a button that says "Open item", which when I click only takes me to my OneDrive on my internet browser. Also, this error only happened after I moved two of my documents to a new folder within my drive. I have tried the Repair Tool and it did nothing. The items that say they can't sync keep changing as well, so I have multiple documents that won't sync apparently.