add weight in datacard

Hello, i am trying to get the weight to be added to a custom properties field when adding a file to the EPDM vault, does anyone know how to do this? i have the "weight" line in the custom properties in the assembly template like shown . What am i doing wrong because it is not adding it to the custom properties when i drop the file into the vault, it deletes the weight line, the part/assembly that i am wanting to add to the vault  do not currently have it in the custom properties but i was wanting to add it automatically so i didn't have to go into each file and add it manually.

any help will be appreciated.

SolidworksAssemblies