I think I must be misunderstanding something basic because I am having difficulty stopping Storyboards that have their RepeatBehavior set to Forever.

When I call Stop() on the StoryBoard it doesn't seem to do anything. I also tried called Remove() after stopping it and that doesn't seem to do anything. After all that I checked IsPlaying() and it is returning true. The animations stop correctly in the XamlPlayer.

This must be a very simple thing to do, but I am at a loss.

Only Storyboards that have been started with the IsControllable flag set to true can be paused, resumed or stopped.

This flag can be set to true when calling Storyboard.Begin(): Or if Storyboard is started by a BeginStoryboardAction, the action must have its Name property set: If you are already following these stpes and you are unable to stop the animation it could be a bug, please report it in the bugtracker.

Thanks, setting that flag true fixed my issue.