How to return a borrowed license early in Flexlm. The Phantom User issue!

The problem:

So you have network licensing and/or multi-user seats of software and some of your users borrow licenses so that they can access your licenses off-site. Life is happy and the world is a Sunny place but then a PC crashes. Or perhaps an employee leaves and you forget to return the license. The license is consumed and there might be a Phantom User lurking in Flexlm (sounds like a good title for an electronic music album?).

The solution:

There is none. Well, OK, officially Autodesk states that the only thing you can do is wait out the borrowing period but that’s pretty hard going when you need every license you own!

So now that your heart rate is back to normal, there is a way which we have tested that gets you the result you need. It involves modifying the registry so of course we have will give you a warning about the risks involved in doing this – make a backup, etc. But here goes:

  1. On the client machine use Regedit to delete “HKEY_CURRENT_USERSoftwareFLEXlm License  ManagerBorrow”. Once deleted, restart the CAD application and borrow the license. You should now be able to return the license.

And, if that fails there is yet another workaround might be to exclude the IP or a”phantom” user’s PC from borrowing anything thus returning the license:

  1. Create an Options File –MORE HERE and place it in the same folder as the license file. Block the ability to borrow specific licenses. Any users, hosts or IP addresses not explicitly excluded will continue to have the ability to borrow licenses. Here is the syntax:

EXCLUDE_BORROW [productfeature] [type] [name]

The following example blocks borrowing a subscription license with multi-user access of AutoCAD for a variety of types:


IP address might be better if the user profile on the same PC has changed. If the user-profile still exists then you can try using the user profile (network login) to do this.

One the above methods will get the license returned one way or another! There are other more dramatic methods that return all your borrowed licenses but that is very disruptive. This is quite an elegant workaround.

Of course prevention is better than a cure so consider this:

  • It is strongly recommended that network administrators limit network license borrowing to those users who specifically need to take licenses on the road. It is strongly recommended that administrators set the maximum borrow period to an amount of time that corresponds with how long these users will be away from the license manager. These settings are controlled using an options file. For more information about configuring an options file see the following solution: Controlling network license access using an options file.
  • Do not use the Borrowing tab in LMTOOLS with Autodesk product licenses. Doing so can cause additional borrowed licenses to become orphaned from the license manager.

Have fun, Mark Kelly