Microsoft OneDrive is experiencing intermittent issues affecting all users
portal.office.com
portal.office.com
There is a parallel thread which mentions Skype as being affected too.
https://news.ycombinator.com/item?id=13924838
I guess this across all of Microsoft's offerings.
Current status: We're deploying a fix to restore service. Users should begin to experience service restoration as the fix is rolled out.
Current status: We've determined that the previously resolved issue had some residual impact to the service configuration for OneDrive. We're performing an analysis of the affected systems to determine what further steps are needed for full recovery.