QUESTION:
I am trying to import settings from my sandbox (which is running version 3.8) to my production org where I just installed version 3.9 and keep getting an error "Settings file is invalid". How can I resolve?
ANSWER:
Settings are not compatible between the old 3.8 release and the new 3.9 release. To resolve you will need to upgrade the sandbox to 3.9, then re-export the settings and use that settings file to import into your production org running 3.9.