When using the offline editing plugin in QGIS to make a remotely accessed PostGIS layer editable offline, I have found that if there is a problem it is possible for my project to become stuck in offline mode. This means that the project only has the option to synchronize and the project can no longer be used to open a PostGIS layer and convert it to an offline project.
This has happened when the offline SQLite file has been moved, overwritten, created on network drive that is no longer accessible or the layer has been removed from the project while it is still offline.
I have also encountered problems when the synchronize has not worked, perhaps QGIS crashes or the connection to the database drops out. (Problems can be caused trying to Sync unsaved layer edits, or having other QGIS windows open that if interacting with them when syncing causes QGIS to hang).
Is there a way to 'repair' the project so that it's offline status can be reset?