An ActiveEntity exists with no related result and no operand.
An active entity exists without a related result: Missing the StructOperation_RSLT1 relationship to PlateGeometry PlatePlanningSplit_AE, ProfilePlanningSplit_AE, PlateDesignSplit_AE, PlateCutout_AE. The active entity is also missing its related (input) operand.
You cannot manipulate the object itself or other objects related to it.
What You Should Do
Ask your database administrator to back up the model.
Supply all information possible that may have led to this situation, and submit this information along with the backup to Smart 3D Support.
Delete the object using one of the following methods:
Select the object in the Workspace Explorer, and delete it.
Run the Clean Database custom command to delete the object.