The days of permanent "license keys" (serial numbers) are largely over for Autodesk products . Modern versions like 3ds Max 2023.3 use . This means your "key" is actually your Autodesk Account login credentials.
If you are learning the software, you don't need to hunt for a "crack" or a leaked key. Autodesk provides a Free Student Version that is identical in features to the professional version. autodesk-3ds-max-2023-3-license-key
If you already have a legitimate seat but are seeing "License Error" messages, it is rarely a problem with a "key." Instead, it is usually a communication error between your computer and Autodesk's servers. The days of permanent "license keys" (serial numbers)