RO-Crate: There is no pointer to the root dataset

[pdurbin]

I'm getting some strange errors when I try the ro-crate-metadata.json file from the zip at https://dataverse.lib.virginia.edu/file.xhtml?fileId=79676&version=1.2

Uncaught (in promise) Error: There is no pointer to the root dataset
    u https://gdcc.github.io/dataverse-previewers/previewers/v1.4/js/ro-crate-dynamic.min.js:29
    h https://gdcc.github.io/dataverse-previewers/previewers/v1.4/js/ro-crate-dynamic.min.js:29
    <anonymous> https://gdcc.github.io/dataverse-previewers/previewers/v1.4/js/ro-crate-dynamic.min.js:29
    <anonymous> https://gdcc.github.io/dataverse-previewers/previewers/v1.4/js/ro-crate-dynamic.min.js:29
    <anonymous> https://gdcc.github.io/dataverse-previewers/previewers/v1.4/js/ro-crate-dynamic.min.js:29
ro-crate-dynamic.min.js:29:151715

Here are the errors in context from https://demo.dataverse.org/file.xhtml?persistentId=doi:10.70122/FK2/5BRA4M/MKCFRV&version=1.0

Here's the PR where we originally added the RO-Crate previewer:

• RO-Crate previewer #41

It seems to work fine on simple files. Below is an example from https://demo.dataverse.org/file.xhtml?persistentId=doi:10.70122/FK2/RS3ZA9/CEFMAO using this ro-crate-metadata.json file.