*Update*
If you are still experiencing sync errors and did not report your problem to the IT Support Centre, the following update may resolve your issue. This will apply if you have Office 2013 and receive a “Credentials needed” prompt when attempting to sync. Office 2013 update (KB2986219).
https://support.microsoft.com/en-us/kb/2986219
This update can be manually downloaded and installed from the link provided.
If you are still experiencing sync issues after applying the update or require assistance with the update, please contact the IT Support Centre.

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Previous Description (2015-10-16 08:58:20):

Starting on October 15th, the IT Support Centre started to receive an increased number of calls about OneDrive for Business failing.

Users have reported red X's beside their files and the client reports sync errors are present. Attempts to repair the sync fail.

Microsoft is aware of the problem and report that not all customers are affected. They are currently preparing a fix.
If you are experiencing this problem, please contact the IT Support Centre or submit an online help form as we would like to track the extent of the problem and to ensure the fix is applied when available.