Menu override minecraft?

How can I get the normal Minecraft menu back without having to uninstall a mod

Deactivate the modern in the mods tab.

Should work.

What do you mean by modern

The modern Minecraft mod

I don't think you can do that without disabling a mod. Have to look for something with your mods with Custom_Interface or Custom_Menu or something and just write ".deactivated" behind it

I found a main_menu.class file,

but if I delete them, Minecraft will crash at launch