hm interesting.
Do you have IE11 installed on the device with Xibo for Windows?
If yes, could you check if you have correct entries in Windows registry regarding browser emulation?
Enabling HTML5 in the Windows .net Player
1.7.8/1.7.9 players should make those changes during installation.
If no, then please install IE11 and make those registry changes.
Finally is it publicly accessible? ie could you give me the source of it / your exported layout so we can test it in our office? (if yes, send my a pm please)