hi,

1. download addon (i.e. "GearScore3.1.15[1].zip")

2. unpack the zip - you get the folder "GearScore3.1.15[1]"

3. not just copy the complete folder to your addon-folder

4. exctract all folders from within "GearScore3.1.15[1]" to your addons

should work, it did for me