A synchronization protocol is provided that can be used to resolve synchronization errors encountered while trying to synchronize versions of data objects between a client device and a remote computing system. The protocol includes a client device, in an offline processing mode, handling user interface (“UI”) manipulation actions on one or more UI elements of one or more UI screens. The handling of the UI manipulation actions modifies or creates a local version of a data object stored on the client device. The UI manipulation actions are stored by the client device and sent to the remote computing system. The client device receives a synchronization error notification from the remote computing system. After receiving the notification, the client device displays, in one of the UI screens, the local version of the data object and one or more indications of a synchronization error.