How come the 3dmax perspective window doesn't show up, no lines or patterns. Objects are in perspective view.

Hello

If the model you created in other view can be viewed in perspective view

Then you can click on the "+" in the upper left corner of the viewport ? In the Viewport Settings pop-up, switch to the Background panel and choose to use a custom interface gradient color

If you can't view the model in perspective in other views, it may be a problem with the graphics driver or the software's display driver

Try updating the graphics driver to the latest version, then go to the Customize - Preferences - Viewports section and click on "+" in the upper-left corner of the viewport. -Preferences- Viewports, change the display driver mode (I'm using the software's recommended Nitrous mode)