If the product key is flagged as incorrect, it may be because of a mismatch between the standalone product and a suite installation. Trial Issues:

For official support or legitimate activation of older versions, you may need to reach out to Autodesk Support

Unofficial download sites are a primary vector for ransomware that encrypts your local files.

To help find the right setup for your engineering workflow, could you clarify:

Autodesk Inventor 2012 is a 3D CAD software that allows users to create, simulate, and test digital prototypes. It is designed for engineers, designers, and manufacturers who need to create complex 3D models and assemblies. The software offers a range of tools and features, including: