typing in http://10.102.250.91/webui/image/service/03/video/1 is returning a static image.
Inspecting it however shows it's not an image that is returned. It's a html with an img tag with as source the same url that I entered. 
Of course, this then doesn't work when I try to show it in a video thumbnail. It remains just a black screen
http://10.102.249.11/VideoThumbnails/Video.htm?type=Generic%20Images&source=http%3A%2F%2F10.102.250.91%2Fwebui%2Fservice%2F03%2F1&refresh=1000
Does DataMiner already have an option to display thumbnails like these?
The VideoThumbnails can only be used with images/videos, but not with html pages. Html pages can be shown directly in a Visio or dashboard.
However, it might be that when opening an image url in Chrome, that Chrome wraps it in an html page to be able to display it, so the F12 inspector might be misleading. It would be better to look at the network tab, or to use Wireshark.
When opening the VideoThumbnails url, what do you see in the F12 dev tools on the network tab (make sure to open F12 before opening the url)? Are any calls failing?
An URIError gets thrown when the source url is not valid, for example when it has been incorrectly “url encoded”.
We were able to resolve it partly, but we’re currently waiting on documentation on how to authorize on the device for retrieving the thumbnail.
There is an uncaught URIError: malformed URI sequence on http://10.102.249.11/videoThumbnails/scripts/JavaScript.js
The problem with just showing the html in the Visio is that it’ll not refresh automatically. Or is there a way to do this?