When you try to open a published application or remote desktop you are receiving the following message:
"The connection was ended because of a network error. Please try to connecting to a remote computer again. (0x87650000) "
WebSocket header is blocked by hardware/software router or firewall. If you open a debug console in your browser (e.g. Firefox, Chrome), you will see the particular error message '404' regarding WebSockets.
You can easily check by yourself as on the screenshot below (open a published application or remote desktop> Press F12> Network tab> WS> RDP)
To solve the issue you need to check