When configuring the Autodesk Network License Manager and you get this error:
FlexNet Licensing error: -97,121
The first thing I do is check out our Knowledge Article here:
http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/Common-FlexNet-error-codes.html
This error basically means that the the software and license are not working. The easiest thing to do is to look at the log file to find out what is causing the error. To get to the log file, go to the Config Services tab and click on View Log or look for the file in the path.
1. In the log file, the error is below and the problem is that license has expired.
9:02:32 (adskflex) EXPIRED: 65300ARCHDESK_F
One such type that will expire are typically previous use licenses. Please check out the blog post here for more info on it:
http://upandready.typepad.com/up_and_ready/2014/01/previous-use-license-request-running-software-that-is-more-than-3-versions-back.html
2. In another log file example, the error is:
9:22:06 (adskflex) Invalid license key (inconsistent authentication code)
In some instances, if you are moving a license from one server to another server, you may want to save time by editing the ethernet address in the license file. This will not work. You must generate a NEW license file for the new server. The MAC address listed at the top of Autodesk license files are encrypted into each product increment and cannot be manually edited without invalidating the license file.
http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/Error-Invalid-license-key-inconsistent-authentication-code.html
Reference
http://upandready.typepad.com/up_and_ready/2011/11/quick-start-setting-up-a-license-server.html