When changes have been made to the source asset after a task is created, the following message appears:
Changes have been made to the asset after the task was created. If you continue to edit the currently selected task you will be editing an old copy of the asset. To edit a new copy create a new task. Use the viewer to determine what changes were made.
The source asset may have changed as a result of an update. In this case, save your current work into a TM and create a new project (or request that a new project be created) containing this changed asset.