Object Type in the To Do List: Plate system.
Meaning: The boundaries do not form a closed surface. You might also see this error when boundaries for an existing plate system are modified.
Verify that all of the boundaries form a closed region at the Molded Forms system level. If the boundaries do not, you might need to modify the existing boundaries or add new boundaries.
Example: The molded surfaces of the plates do not form a closed boundary at the arrow.
Recompute the plate system.
Verify that the plane inputs for the plate are valid.