Trimble Connect Shared Viewer "Model is Corrupted"

I have a project that is shared through the TC viewer. I am repeatedly getting a “File Corrupted” message. I have used this service successfully before and never seen this warning, the file appears to be functioning OK.

Sometimes one gets a clue when clicking on an element, hit the ‘i’ to get the details on the right and look for ‘import_plugin’ property.
What format is used?

Thanks for the assist. Sorry to be dense, where is the “i” to get the details? Is it the three dots at the top of the hierarchy? If it get details there this is what I see:

Selecting in the model tree or in the viewer should trigger the dialog with the options:

Great, thanks for that hint, got it now. However I don’t see any “import-plugin” property so perhaps that’s not the problem here. I continue to see the corrupt warning , especially when isolating single elements visually. But the app does continue to run so perhaps its no big deal.