Hi Ben,
Have forwarded your question on to Amy who's a bit more au fait with licensing issues.
Just for further clarity, do you know which version of Maya/Ziva/OS the scene was constructed in, and also your own configuration?
Are you running multiple instances of Maya with Ziva loaded? Could be wrong but you may be limited to one session on the Eval.
If it wasn't for the no license thing, I might have suggested checking for a missing alembic that those tissues were attached to. Or perhaps another custom node in the setup that was required.