The typically pops up when your software tries to grab a license from a server it can't reach, or when the license type it's looking for doesn't match what you actually have.

%localappdata%\Autodesk\Web Services\LoginCache\

Restart the Autodesk Licensing Service and relaunch the product.

The typically occurs when Autodesk software cannot communicate with the license server or find a valid seat. This error is common in multi-user environments for products like AutoCAD, Revit, and Maya. Common Causes

How to Fix 'Your AutoCAD License Is Not Valid' [8 Solutions] - ZWSOFT