Before starting using the addon, you have to define some properties in the Addon Preferences Panel.
Material Library Path:
This is where all your saved materials and icons will be stored, and where will you have to go if you want to delete or manage all your materials.
Always make sure that you are NOT using relative path in this file path
Keep this option disabled when selecting your material folder
Pie Menu Properties
These are some settings that will change the number of materials that you want to be displayed when accessing the pie menu. change this setting if you have a small or large screen on your computer.