Cells Synck stop to sync with error empty idToken

Hi. I need help with it.

I have Pydio Cells Home Edition 2.1.2 on Ubuntu server
and using CellsSync-0.9.1

time to time It stops to sync with message in the CellsSync task: Cannot Stat Root: empty idToken
and I need to remove my account in CellsSync and add it again to have it working back.

Does anyone know why it happens?
I have checked the Pydio configuration file and it has not any parameter for set Token expiration time or something related to that.


discussion continued in https://github.com/pydio/cells-sync/issues/29