Unable to create a task for internal customer

Hi,

I am able to create a Incident for a IB instance which shows that the product is at the product warehouse, however I am not able to create a task for the same because of the error message "You cannot use the address you have selected as a incident address for a field service task. You must supply an incident address that has been created as a customer address. Either select an existing customer address or create the customer address first".

I have also created the customer address, but still getting the same.

Please assist.

Thanks.