DEFINE REUSABLE OBJECT IS GRAYED (NOT SELECTABLE)

Hi good people,

I have some question, my reuse library folder is not writable. How to make it writable again?

My purpose is to use Define Reusable Object but the commad is grayed (not selectable), how to fix this issue??

Define Reusable object is grayed (not selectable)the alert message : folder is not existing/ not writable