Something similar happened to me when I was building the Trimble Connect–VIKTOR integration. The viewer failed during startup with an error saying it couldn’t read ‘sessionStorage’. I think this is because VIKTOR loads the viewer inside a sandboxed iframe without ‘allow-same-origin’, so the iframe ends up with origin null and Web Storage is blocked.
What worked for me (kind of) was creating a download button to download the HTML, and when you click it, it opens in a new tab in the browser.
It would be nice to find a safe way to overcome this because I think there are lots of potential integrations we could miss out on.
