multiuser.nsh define issues

I'm having trouble getting even simple barebones examples for multiuser.nsh to work. It seems that things like APP_NAME are defined somewhere in the chain of include files for multiuser.nsh, as I never defined anything on my own. When I try to define things like MULTIUSER_MUI it says that it's already defined as well. This is on v2.42.

Any ideas on how to fix this or if it's a bug?

Thanks!

What exactly is APP_NAME that you mention? It's not present in MultiUser.nsh or the documentation. As for MULTIUSER_MUI, it works fine for me. Can you include a minimal script example that fails for you?