Free Educational Licenses - Arnold User Guide
Getting Technical Support for Autodesk Licensing
Autodesk licensing is supported by the Autodesk support team. To contact Autodesk support, log on to your Autodesk account, and go to https://knowledge.autodesk.com/contact-support
Schools can get free Arnold licenses from the Autodesk Education Portal.
Sign in as an IT Administrator (individual students and teachers can't get free educational licenses).
https://www.autodesk.com/education/free-software/arnoldThe education portal will give you an Autodesk serial number.
Go to registeronce.autodesk.com to register the serial number.
Then go to autodesk.com and sign in to your Autodesk Account. Arnold will be listed under your account, and you'll be able to generate a network license.
To use your new Autodesk network license file
Set up the Autodesk Network License Manager (NLM, sometimes called CLM)
Set ADSKFLEX_LICENSE_FILE on the render machines
Info: There's full documentation here in the Autodesk Knowledge Base.
Arnold support wrote a shorter version of the Autodesk licensing docs.