One of our clients reported an error when trying to install one of our packages in floating mode. The error occured on the client side even though the server was up and running and all the licenses were available.
The error was resolved by opening a port for the artwork.exe daemon on the server. The user also had to specify the port number in the VENDOR line of the license file.
SERVER ASMS44 1866da9faff6 27005
VENDOR artwork c:\flexlm\artwork.exe PORT=1800
See the page Ports used by License Manager and Daemon for a detailed explanation of how to set the ports and how the firewall on both the license server machine and client machine should be configured.