Error: eBay Refresh token not valid

Problem:

eBay requires you to regenerate your refresh Token after any of the following

1. After 18 months.
2. After a change in account details (password, business name, address, etc).
3. eBay revokes a token due to security reasons 

If this is not regenerated, you will receive an error "eBay Refresh token not valid"

Solution:

Go to Sites -> [eBay Site] -> Credentials ->

Then follow the steps Get eBay Refresh Token