Cannot derive Vaulted assembly

[bcrowell]

There is an assembly in Vault that I need to derive into a single part to work with our CMM software.

When I try to open up the assembly from Vault, it opens up just fine, with no warning or errors or save prompts, so all part data links should be ok.  However, when I try to derive it there is a part that will not come in.  If I derive the assembly and keep each solid as a solid body, it derives just fine but that is not what I need.

Is there any way to troubleshoot why a file isn't coming in for the derive but works just fine with Vault?  I can't attach the assembly but I will try to attach the process I have recorded and have a screen clip of the error message.