[gardian]

Hello
I would like to ask you I receive an error while I m trying to change a material property in Workbench.
I created a new material library
I added to engineering data Location
I broke the link to source and I m trying to add a new property to a material ( renamed ) like air . density .
When I go to physical properties-> density -> right click (include property to material)
I receive an error :
Specified property –Density not exist .
Do you have an idea why is that ?

What I m doing wrong .? do I need any patch of Ansys or something in the installation ?
I m using Ansys 12.1 and I receive the same error with all properties of materials ..

Thank you