Problem Definition
It is not possible to launch applications from Web Interface or from the online plugin.
The following error occurs.
"Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. The Citrix XenApp server you have selected is not accepting connections."
In the farm there are provisioned and non-provisioned servers. Only sessions that launch on the provisioned server are affected.
Troubleshooting Methodology
It was noticed that sessions launched using an ICA client directly on the provisioned servers themselves did not show the problem. However, any session launched from a remote PC did not launch.
It seemed like a networking issue; however, the server was pingable from the remote locations and ports were opened. Indeed sessions launched using the quicklaunch tool from the remote PCs were launched successfully.
Then we checked the ICA file that was generated in Web Interface when launching an application from the remote machine. See below for how to do this.
The file showed the following.
[TSTNA45A User Desktop]
Address=10.0.0.2:1494
The Web interface was showing s the wrong IP address. The address shown was on the internal Provisioning Services network instead of on the production network network where the users reside.
It was then revealed that the provisioned servers were multihomed. The XenApp servers were incorrectly creating ICA files with the internal network address.
Resolution
The solution was to edit the ICA listener so that it listened only on the production NIC. We changed the Network adapter setting from All Network Adapters to the external NIC only.
Now the ICA files generated had external addresses and all users could launch applications.
More Information
CTX122536 – Citrix Quick Launch
CTX124414 – How to Obtain an ICA File Through Citrix Web Interface 5.2
This document applies to:
Source: CTX128254 – Case Study: Error: Unable to launch your application. – Citrix Knowledge Center
