If you are unable to communicate with the flexlm network license manager (i.e. you receive an error or the license finder dialog when launching the program), but the license manager shows licenses are available and is the right version, then there are a few common things that will cause this to happen. If you have not upgraded to the latest version of FlexLM you may want to do that first and see if the problem persist. To see what versions of Flexlm you need please see our bog at: http://blogs.rand.com/support/2012/01/i-just-received-2011-do-i-need-to-upgrade-the-license-manager-for-network-licensing.html
1) In the programs folder (where the .exe is you run to open the program) there is a licpath.lic file. It could have an incorrect server name. Open it in notepad to verify it has the right server name in it. Also after the server name there should be a space and twelve zeros
SERVER servername1 000000000000
You can receive the license finder dialog if the 0's are missing too.
To see more information about the licpath.lic please see our blog at: http://blogs.rand.com/support/2012/03/licpathlic-is-tasty.html
2) Incorrect information in the registry. This one is not for the faint of heart. In the Registry editor expand out hklm->software->flexlm license manager and double click the ADSKFLEX_LICENSE_FILE key. If the value is incorrect then this can also cause this issue. It should be "@servername" where "servername"= the name of the server that is running the license manager. If there are multiple license managers on the server, it may be a good idea to preface the entry with a 2080 so it's 2080@servername. 2080 is the port that is registered to Autodesk specifically for this use.
Warning! Problems caused by improperly editing the Windows registry could render your computer/operating system unusable. Microsoft provides a wealth of critical information that you need to know about the registry in the Microsoft Knowledge Base.
Use the Microsoft® Registry Editor only at your own risk and only after backing up the registry as well as the system.dat and user.dat files as outlined for your operating system in the Microsoft Knowledge Base and in the related Autodesk solution, http://usa.autodesk.com/getdoc/id=TS66513. Additional information about the registry is also contained in the Help topics in the Microsoft Registry Editor.
3) Incorrect information in the Windows Environment variable for ADSKFLEX_LICENSE_FILE in the System variables. It should also be formatted like the registry. "@servername" just like the registry setting above.
4) This is the new one starting with the 2010 release. There is a file (hidden deep down in the system) that is called CascadeInfo.cas. This file can become corrupted. To replace it, rename the file and launch the program again, it will ask the license manager for a new one and will be created on the fly. On an XP machine look under C:\Documents & Settings\All Users\Autodesk\ADLM. On a Win 7 or Vista machine it'll be in c:\programdata\autodesk\adlm.
Warning: Do not delete or rename or open the ProductInformation.pit file.
5) A firewall is turned on and blocking the ports Autodesk uses: Ports 2080 and 27000-27009. Ensure you can ping the license managers ip address and hostname and also telnet through port 2080 from the windows command window (start>run enter CMD and click ok).
TELNET ip.ip.ip.ip 2080
Where ip.ip.ip.ip is the license manager's actual ip address.
Those are the five main causes for this issue, however, I've seen others but they're rare.