I am in a project and edited one of the standard masks. I'm going to use it again in the project and thought I might use it again in others and so tried to save it. Got the message that you can't save with a video clip and so I replaced the clip with an image and saved it. When I'm in that image clip I can see the name I saved but when I go to any other clip and enter mask designer there is no sign of it. What am I missing?