Unable to import projects created by MetaMatrix 5.5.x

Importing a Model Project Set (MPS) from the MetaMatrix 5.5.4 Getting Start Guide tutorials yields no visible results, no errors, but a phantom project exists in the workspace.

Trying to import the project from an unzipped MPS provides better results, but I found one of the relational source models was consistently corrupt.

Perhaps things aren't as bleak as they seem, but this all needs to be clearer for the "hapless user". (I'll attach the MPS.)