Performed a rollback on some files in EPDM. Only went back one version. Went from a Released state, to In-Work. Rolled back to its Released state. All the files can be transitioned to another state except the top-level assembly. I get this message when I try to transition from EPDM:

When attempting to do it from inside SolidWorks:

I've tried checking out the assembly, saving it, and checking it back in (to create a new version), but still cannot transition the state. Any ideas on the problem, or a workaround?