Showing charts using web widget?

I’m trying to show an openHAB chart using the web widget.
This URL used to work in the image widget of the old version.

http://192.168.1.91:8080/chart?groups=KwHDay_Chart&period=W&h=600&w=800

All I get now though is a big white box. Should this work?

Ha, doh!

Looks like the URL is case sensitive and I had one letter not in the correct case. Is working now!