RoboForm has confirmed this outage was caused by "Unplanned Server Maintenance".
The maintenance was completed and should no longer affect the synchronization process.
Synchronisation is back up and running, awaiting root cause information.
We are aware of and have raised issues with RoboForm sync errors popping up.
RoboForm are now investigating the cause.
Your passwords are stored both locally and in RoboForm servers, you should be able to use RoboForm to complete sign-ins but currently not share new passwords between team members and saving passwords may fail.
Further updates to follow.