OK so Citrix isn’t something a normally blog about but I ran into this issue today so thought I would share the information. When users were trying to log into the Citrix Web Interface they were receiving authentication failure messages. Upon investigation the Citrix XML service was missing. First I unregistered the service just encase
The server was then rebooted for good measure, the service then needed to be reregistered with the appropriate port. For a default installation of Citrix Access Essentials 2 this is port 8001
Once the service is registered and showing within the services mmc, ensure that the service is started.
If this doesn’t resolve your issue it is also worth checking for the application pools within your IIS sites for Citrix, I found these could be re-added if needed by running a repair installation of CAE.
Finally you can repair your sites within the Citrix Access Management console, please note you will loose any customisation when you do this.
Hope this helps.