3DS Max - Curve Editor Blank - Fixed 

Maybe some 3rd party plugin messed things up for you, I suggest you reset your User Settings: 1- Close 3DS Max 2- go to: C:\Users\YourUserName\AppData\Local\Autodesk\3dsMax\20xx - xxbit 3- Rename the folder called ENU to something else like ENU.old 4- Restart 3DS Max Note: AppData is a hidden folder, so you need to enable the visibility of hidden files and folders From the Control Panel Also, by doing this, you'll lose any custom UI configuration Or any custom 3rd party Macroscripts you installed(but you will not lose plugins you installed using an exe installer or something like that, for example V-Ray renderer, etc,...), and you'll have to reinstall them again. If renaming the ENU doesn't help, then close Max, delete the newly created ENU folder, And then rename the old one ENU again, this way when you restart 3DS Max you'll have back All your custom UI settings and 3rd party Macsroscripts.

@@Kranos_CG I use these tools from time to time. I'm lazy to upgrade to Max 2025.