ImportError: cannot import name 'ConstantProperty' from 'modular_tree-blender_31.m_tree' (unknown location) Really love this addon, has anyone got it working with Blender 3.1.0 so far??

Don't know how to fix that, but I manually go into C:\Users<user>\AppData\Roaming\Blender Foundation\Blender\3.2\scripts\addons and delete the modular_tree folder (when blender is not running).