What is this drawing icon?

I have a weird drawing I just pulled out of PDMWorks, it's a drawing of an assembly, with no assembly in the vault. but everything works on the drawing except I can't do anything with the views or open the assembly. And the feature tree has different icons than normal, it's like a blue chain link below it.

If I look in "Find References" it says it couldn't find the assembly, if I try to open the assembly by right clicking on the view it brings up the window asking if i want to browse for the missing files or suppress them. This isn't my drawing so I don't know where the assembly could be saved on our network.

Does anyone know what these icons mean or what I can do so I can open the assembly to work on it? (that's where the changes I need to make are)

Thanks in advanced for your help.

SolidworksDrawings And Detailing