Floormaster.dgnlib file

I am using Aecosim SS6. I open Floormaster.dgnlib file and create Building and floor. After doing this I try to create my gridsystem. When try to save this I get the following message:

''The originating application (48760) has intentionally restricted changes to this element.

This was done to maintain the element's design integrity. The originating application (48760) must be present to modify this element.''

Could anybody help me please???

Thanks

George