To understand the significance of version 2.4.5, one must first grasp what the plugin actually does. VRM is an open file format for 3D avatars that is particularly suited for VR (Virtual Reality) applications. Unlike standard 3D model formats (like FBX or OBJ) which only contain geometry and textures, a VRM file contains a wealth of standardized data, including:
If Unity asks to upgrade your scripts, click "Yes." 2.4.5 vrm plugin