The model could not be saved to the cloud due to an error.
Warning: Sync with central failed. You don't have access to the cloud folder.
Issue: Your cloud model was not saved to Autodesk Docs because of a linked file using a shared site. When linked files use shared sites, the host model must be saved prior to sync with central.
Solution: When working with shared sites on models using Autodesk Docs it is a best practice to save the model locally before you attempt to sync with central. Save the project locally and then attempt the sync with central action again.