TypeError: Cannot read properties of null (reading 'getNamedViews') when trying to display Navisworks files in a Autodesk Forge Viewer

I'm getting this error in console when I use viewer.start() to start a Autodesk forge viewer when I'm trying to display Navisworks models (.nwd/.nwc files). For .rvt, .fbx, .3ds, and .max files everything seems OK.

GuiViewer3D.js:244 Uncaught (in promise) TypeError: Cannot read properties of null (reading 'getNamedViews') at Object.addViews (GuiViewer3D.js:244:40) at SvfLoader.js:256:31

This error references the following in GuiViewer3D.js:

And although the viewer will launch, it won't show any model:

Here is my code:

const lunchViewer = (urn) => {
    var options = {
        env: 'AutodeskProduction',
        getAccessToken: getForgeToken,
    };
    var documentId = 'urn:' + urn;

    window.Autodesk.Viewing.Initializer(options, () => {
        window.Autodesk.Viewing.Document.load(
            documentId,
            onDocumentLoadSuccess,
            onDocumentLoadFailure
        );
    });
};

const onDocumentLoadSuccess = (doc) => {
    const geometries = doc.getRoot().search({ type: 'geometry' });

    if (geometries.length === 0) {
        console.error('Document contains no geometries.');
        return;
    }

    const viewerDiv = document.getElementById('viewer');
    const config = {
        extensions: [
            'Autodesk.DocumentBrowser',
            'Autodesk.Viewing.MarkupsCore',
        ],
    };
    const viewer = new window.Autodesk.Viewing.Private.GuiViewer3D(
        viewerDiv,
        config
    );

    const initGeom = geometries[0];
    const svfUrl = doc.getViewablePath(initGeom);
    const modelOptions = {
        sharedPropertyDbPath: doc.getFullPath(
            doc.getRoot().findPropertyDbPath()
        ),
    };

    viewer.start(
        svfUrl,
        modelOptions,
        onLoadModelSuccess,
        onLoadModelError
    );
};

I'm using the above approach to be able to add multiple models in a same viewer. And also to switch between views in the same loaded model in the viewer.

This is a known issue, which has been fixed in viewer v7.93. Please try to upgrade it to v7.93 to see if it helps.

For older versions, please consider GuiViewer3D#loadDocumentNode instead.

Here is an example util demonstrating how to aggregate multiple models using GuiViewer3D#loadDocumentNode:

https://github.com/yiskang/MultipleModelUtil