This most typically occurs when you try to open a Dashboard on a iPad or iPhone. It can also occur if the user's IT department blocks all .htm files.
In a recent update to the iOS operating system, local HTML files are now opened in a preview mode and not the full Safari or Chrome browser. If you try to open a Dashboard on an iPad or iPhone, you will get this error message:
We have requested a solution from Apple, but none has been forthcoming. There is one workaround, however.
We can upload the file to a server and provide a link that will open on any device. including iOS sevices like the iPhone or iPad.
Send us the .htm file (not the.txf file) and we will upload it to the server.
UPDATE: You cmay be able to do this yourself. Here's how: https://www.taptest.co/upload-dashboard-to-cloud.html