I recently had a problem with AutoCAD 2006, the Network License Server (aka FLEXnet 10.1.5) and a borrowed network license.
The problem was that a laptop had borrowed a license and the hard drive died several days after.
A support call lodged with Autodesk resulted in a "wait for the borrowed license to expire", even after escalating the request to a supervisor. Sorry, not good enough. The annual maintenance fee paid to Autodesk should more than make up for either an immediate remedial action (ie an administrative return process that actually works), or a temporary key re-issue.
So I started Googling. I Googled some more and became thoroughly depressed. Yet another one of those well-known, but not one of those well-documented, products. I'll save my rant about large software companies who don't care about their customers for another day.
There was one useful poster on the Autodesk forums, who was careful with his information in a bid to retain his posting privileges to the Autodesk forums. Based on some of his information, I was able to finally come up with a solution.
The FLEXnet licensing "solution" under Windows provides a GUI front end (called LMTOOLS) to the lmutil command line utility that is used to manage FLEXnet license manager under Unix.
The last tab of the LMTOOLS utility is called borrowing and it's supposed to be used to be able to manage licenses that support borrowing. However it doesn't work out of the box and furthermore Autodesk do not recommend nor support the use of this tab for their licenses.
For anyone that wants to get it working, you need to go to the Utilities tab, leave Vendor Name blank and enter the path to the license file containing the floating licenses. Click Override Path. This will set the default path to the license file. In Vendor Name, enter 'adskflex' and use the same path as the previous step, then click Add Vendor Path. This will enter the vendor path for Autodesk products to point to the license file. You shold now be able to go to the Borrowing tab and click List Currently Borrowed Features to see the borrowed licenses and to also use the Return Borrowed Licenses Early button.
In my case, the Perform Status Enquiry on the Server Status tab was showing the AutoCAD license as being borrowed (by the presence of a 'linger' value), but the List Currently Borrowed Features command on the Borrowed tab indicated that no licenses are borrowed. This was most likely due to the fact that I had consolidated several different vendors' FLEXnet licenses under the one FLEXnet license server to improve license server reliability (which it actually did - a whole heap of ongoing random license server crashes disappeared once consolidated)
So, it appears that the Network License server + utilities are half-baked and the only resolution I had according to Autodesk was to wait the 2-odd months for the license to expire.
In a final act of desperation I started up the Network License service and watched its progress using Sysinternals' Process Monitor and found the location of the stored borrowed license. The borrowed license was stored at:
C:\Documents and Settings\All Users\Application Data\Macrovision\FLEXlm\adskflexborrow
I would expect to find an 'adskflexborrow' file on a Unix system that hosts a FLEXnet license server, for those people running on Unix.
After backing up this file and stopping and starting the Network License Service I was able to reissue the license.
Why the Autodesk Help Desk weren't able to tell me this is beyond me...