When I setup my server, I had used the farm automatic settings for licensing information. For some reason, the server had not properly picked up the licensing information from the Citrix 3.0 farm and it stopped accepting connections because licenses had expired. I used the "chfarm" command to remove the server from the current farm and put it into its own farm. I then ran the "chfarm" command again to bring it back into the metaframe farm. This time, I manually put in the address for the licensing server and it has worked since. I am not sure what effect this would have in a single server farm, but it worked in a multi-server farm.
There is an update to this licensing issue. I encountered this problem with a recently implemented Metraframe 4.0 farm. One of the servers kept coming up with the following error: "MetaFrame Presentation Server cannot contact the license server Empty". This occurred after the installation of the new R02 patch for Metaframe. If the patch was removed, the error would go away. Additionally, the error only seemed to occur on startup. As it happened, there was also a red-flag associated with a netlogon error, event id 5719. This suggested the OS and its services were starting slightly sooner than the network was actually available. Upon further inspection, spanning tree was in use in the environment, causing network negotiation to take a bit longer on startup. However, there was also a subtle difference in the server I was using. I had set the NIC to auto-negotiate 1000Mbps, rather than just Auto-negotiate, for the network speed. I had made this change attempting to troubleshoot the netlogon error. Doing so, added just enough extra latency that the IMA service could not contact the license server on startup. Something to be aware of then, when applying the R02 patch, is that it is more sensitive to network connectivity than its predecessors. I had attempted to recreate the local host cache, setup new dsn files, change farms, but none helped this time.
This error appeared suddenly after running for months without any problem. The communication with the license server had been configured using the default settings (port 27000). Most likely, due to an installation of new software, the port for the Citrix licensing server has been changed to 27001. After changing the Citrix settings to 27001, the error disappeared.
See the link to "Citrix Support Document ID: CTX103951
" for details on solving this issue.
As per Citrix: "Ensure the Server Property for the License server is defined to point to a valid License Server and/or configured to point to a valid License Server within the ServerFarm Properties
The licensing client libraries on computers running MetaFrame Presentation Server cache the IP address of the license server. This information is stored in WSXICA. If the IP address of the license server is changed, either manually or automatically through DHCP, the computers running MetaFrame Presentation Server are not aware of the change. Therefore, attempts to contact the license server at its old IP address fail". See the link to "Citrix Support Document ID: CTX103795
" to fix this problem.