I have several thousands of bookmarks but wasn't able to sync them. I always receive the error message: "Sync encountered an error while syncing: Unknown error. Sync will automatically retry this action." In order to solve the problem several times I reset the remote data but always receive the same error appears after retrying. Also I exported the bookmarks and re-imported them (which replaced the existing bookmarks). Still the same problem. Any ideas how to solve the problem?