You attempt to launch a XenApp 7.6 desktop published through NetScaler appliance:
… but notices that you are presented with the following error message:
The connection to "<YourXenAppGroup>" failed with status (Unknown client error 1110).
One of the common reasons why this error would be thrown is if there is a misconfiguration or lack of Secure Ticket Authority (STA) configured in the load balancing virtual server on the NetScaler appliance. To correct this issue, launch the properties of the load balancing virtual server representing the StoreFront servers, review the Published Applications settings and ensure that STA Servers are configured: