New Menu System
One of the new 3dsMax 2025 features is the completely rewritten new menu system for menus and quad menu. This is a part of the initiative called Upgrade-Safe UI which was introduced in 3dsMax 2020 for the hotkeys first.
For users, the most important and beneficial change is how the customization is stored and loaded.
The legacy UI customization system was the “Save and Load” system. When users customize menu items and save them, the entire menu status is saved in a .mnux file. Then, when users load the .mnux file, the entire menu items will be replaced by the content of the file. This causes the following issues.
- Dev added a feature XYZ in a new version and added menu items for that. All these newly added items will disappear when users loaded a .mnux file from an older version of max.
- A user had a plugin ABC and menu items for it when they save the .mnux file. But, the new 3dsMas version doesn’t have the plugin anymore. When users load the ,mnux file, all the menu items for the plugin ABC will remain in the menu and be broken.
To address these problems, the new menu/hotkey system uses a transformation approach. Basically instead of save/load the explicit configuration of the menu, the new system stores only the delta(change) from the default menu/hotkey and applies back the changes and overrides the default status.
This will allow users to keep the changes they made while still receiving updates from the global changes. This also means the menu customization will be portable between versions and machines.
This also means it is very easy to go back to the default menus if you need to by simply choosing the locked “3dsMax Default Menus” configuration. This is the same for hotkeys since they are using the same system. Everybody probably had an experience where you had to jump on other’s max and realized that all the hotkeys and quad menu are heavily customized. Now you can easily revert to Default and back to the custom.
User Settings Folder
The menu file(.mnx) are saved in the “User Settings” folder by default. This folder is in the “Autodesk” folder in the user folder, not the hidden AppData folder. C:\Users\[username]\Autodesk\3ds Max 2025\User Settings
You can also set a custom location using ADSK_3DSMAX_USERSETTINGS_DIR env var.
This means that all these settings will survive when you nuke ENU folder to fix issues. Also, you can just copy everything in this folder to another version or machine to get all the settings in this folder.
Currently the following settings are stored in this folder. Any files in this folder is portable and upgrade safe. When you move version to version. Just copy them to the new version folder.
- Hotkey Set File(.hsx) – need to load to apply
- Menu Configuration File(.mnx) – need to load to apply
- Custom Default File – DefaultParameters.ini
- MaxToA settings
- Viewport Settings Preset – High Quality/Standard/Performance are just presets of Per-Viewport Configuration. You can even make your own, and the own preset settings file is stored in this folder as .json file.
Plugins/Script Developers
The old menu system is gone now. So, Maxscript Menu Manager interface(MenuMan) is gone. If your plugin/script/pipeline has been using MenuMan for adding custom menus. You need to update to the new system.
A good news is that now you don’t necessarily need to code to add menus. The application package now support “menu parts” component. I updated my scMakePreview to demonstrate how you can use this for any scripts.
You can download and check the package. But, in short, I modified the menu and saved .mnx with the new Menu Editor. Then, add the .mnx file in the package and added this line.
<ComponentEntry ModuleName=”./Contents/cui/csMakePreview.mnx”/>
The plugin package will replace the built-in Make Preview viewport menu with csMakePreview like this. 
To assist this, The “Developer Mode”.has been added to the new Menu Editor. When you switch to this mode, only the base and either the selected preset or an empty preset is loaded(no plug-in and user defined menus)to provide a clean configuration to work with.
How to Upgrade/Transfer All Your Customized UI, Preference, Plugins, Scripts
UI
There are 5 UI items you can customize. Mouse, Toolbar, Menu/QuadMenu, Hotkey, Color.
- Hotkeys – If you use a newer than 3dsMax 2020.1, just copy files in the User Settings folder and load your Hotkey Set File(.hsx)
- Menu/QuadMenu – Since the nes system is just introduced(2025), you will get the benefit from 3dsMax 2026. But, if you need to transfer the customization for 3dsMax 2025. Same as Hotkey, just copy files in the User Settings folder and load your Menu Configuration File(,mnx).
- Mouse, Toolbar, Color – These are still using the legacy system. I really hope the 3dsMax dev works on the toolbar sooner than later. For these, you need to load the customization files from an older version.
But! Which file is THE file you need to use? Isn’t there a million places that have ui files? Well… Yes and No. First, the answer to the question is \en-US\UI\MaxStartUI.* files under ENU folder.
C:\Users\[username]\AppData\Local\Autodesk\3dsMax\2024 – 64bit\ENU\en-US\UI\MaxStartUI.*
This is the ui files that gets updated when you close 3dsMax when you turn on “Save UI Configuration on Exit” in the Preference, and they are loaded when 3dsMax starts.
Browse to the 3ds Max ENU folder you want to load UI from and load them. MaxStartUI.cuix is for the toolbar, and MaxStartUI.clrx is for the color. For mouse, MaxStartUI.musx is not automatically generated. So, you can save anywhere and load it.
AGAIN, NOW YOU JUST NEED TO COPY .HSK .MNU BETWEEN VERSION(OR MACHINE) AND LOAD IT TO UPGRADE OR TRANSFER CUSTOMIZATION TO .OTHER MAX
A Friendly Reminder!
Before you transfer any of this UI customization. You need to make sure to install all your plugin/scripts first. For that matter, I already have 3 parts for this. I highly recommend you to read this and try. Since I have implemented this setup, I never ever needed to touch any plugin/scripts install/setup ever again.
/how-to-manage-tools-part-1-scripts-featuring-new-pipeline-integration/
/how-to-manage-tools-part-2-plugins-featuring-new-pipeline-integration/
/3dsmax-2023-pipeline-integration-v2/