Same issue here, tried several methods but none worked.
I've installed 1.1.3 then 1.5.0, not worked.
I've edited the RegEdit to change the location, not worked.
I've copied the "ModoDrum.pak, ModoDrumConfig.pak and ModoDrumFactoryContent.pak" to C:\Users\Public\Documents\IK Multimedia\MODO DRUM\, not worked.
I think maybe if IK develop team can design a little tool to help us to set where the contents should be. Or we just waiting for a fix.
Anyway, I see everyone is providing great ideas to help, grateful!