If you have setup a new XenApp farm and it appears that your applications are launching from Storefront but fail to launch from the desktop with a “cannot start app” error, it may be due to your XML trust configuration setting.
Try: Set-BrokerSite -TrustRequestsSentToTheXmlServicePort $true from one of the Delivery Controllers with the Citrix Snapins added.
This setting is required to trust the XML Service port when using SSON passthrough.