"You are running an unsupported browser. Proceed at your own risk."

If it’s fine in IE, then perhaps try to change registry entry for browser emulation as described in this post:
Enabling HTML5 in the Windows .net Player

Xibo can use chrome (CEF option in CMS) you might want to test with that too.
(display settings page -> edit display profile -> advanced tab -> check ‘Use CEF as the Web Browser’)