You need to login as admin.
Go to your Workspace, open Diagnostics → Interview Packages
Find package for your interview and reprocess it.
If it is reprocessed successfully this message will go, otherwise please provide the error message for package processing.
It means that during the synchronization the server was not able to apply interview received from the tablet. This interview was saved as a package and could be processed later when the server is capable of doing that.
