Sorry you're having a hard time with Rush. Not sure if you've had the opportunity to do so, but I definitely recommend making sure you're running the latest update of Rush, and that if you have any projects that haven't finished syncing to the cloud, that let that process complete prior to adding additional files. Are the .mov files from an iOS device? Are you able to confirm that they play properly outside of Rush? Can you move/copy a single file to a new location and try to add it to a new project to test?