The material menu in 3D is missing. Who knows what happened and how to get it back?

In 3dsmax, the material module is basically integrated in the material editor, which provides the function of creating and editing materials and maps.

Giving objects materials will make the scene more realistic. Materials in 3dsmax describe in detail how 3D objects will reflect or transmit light, and their material properties and light properties complement each other. The final shading or rendering combines the two to simulate the situation of objects in real-world settings. In 3dsmax, you can apply materials to a single object or select a combination. At the same time, 3dsmax scenes can contain many different materials.

Start the 3dsmax software, press the "M" key on the keyboard, or select the "Material Editor" icon from the shortcut menu bar.