Recently I was building a new XenApp / XenDesktop 7.5 environment for a customer. The customer was complaining that when a user changed his printer in Word, the application stopped responding for about 30 seconds. Word showed a message in the bottom bar, “Connecting to printer, press ESC to cancel”. I did not see this before. Further investigation showed that this only occurred when connecting to HP printers which had the HP Universal Printer driver installed. The customer also had Sharp printers, which did not have the issue. Printers where published as a network printer from a print server.
Initially I could not find a solution for the problem. I tried al kind of HP drivers; universal, native, PCL5, PCL6. So I decided to test with the Citrix Universal Printserver. The Citrix Universal Printserver installs a software component on the print server that makes it possible to print without installing drivers on the virtual desktop. On the virtual desktop you have to install a Citrix Universal Print Client. Please note that this is different from the Citrix Universal Client Printer, that makes it possible to print from the virtual desktop to the client attached printers without drivers. Can you still follow me? Here is a short recap:
- HP Universal Printer driver. Driver installed on the printserver.
- Citrix Universal Printserver. Software installed on the printserver to enable driverless printing from virtual desktops.
- Citrix Universal Print client. Software installed on the virtual desktop to enable driverless printing from virtual desktops to printserver.
- Citrix Universal Client Printer. Universal printer in the virtual desktop to print driverless to the endpoint client attached printers.
To be short, when I installed the Citrix Universal Printserver on the printserver, the connecting problems in Word where gone immediately. And I didn’t even install the Universal Print client or configured a policy to enable this. How was that possible? After further investigation I found that the Citrix Virtual Desktop Agent (VDA) has the Universal Print client built in. Bingo! I suddenly understood what was happening. The default installed Citrix Universal Print client always tried to connect to the Universal Print server, even if it was not enabled by policies. It will connect to port 8080 on the printserver and when the Universal Print server is not installed, it waits for a timeout. Somehow this behavior was only visible with the HP Universal Printer driver.
Remove the Universal Print client from the VDA. This can be done by installing the VDA with the parameter /EXCLUDE “Citrix Universal Print Client”. Without this you don’t need the Universal Print server. And all print problems were gone. Removing the Universal Print client will not remove the Citrix Universal Client Printer.