I have written below the problem and how I tackled with this to find the exact solution.
In SAP CRM (Customer Relationship Management), I have a service order in which I have sales relevant items which need to flow in a sales order in SAP ECC (Erp Central Component), and service relevant item which need to be billed in SAP ECC (Erp Central Component) through a debit memo.
Here I have created two different materials.
1: In the scenario highlighted below 168 needs to flow as sales relevant item in SAP ECC.
2: Service relevant material 159 which needs to be billed in SAP ECC (Erp Central Component) through a debit memo based on the work performed by the service technician.
For the reference I have attached some screen shot.
confirmation is not visible by clicking on the follow up to create the service confirmation for the service relevant item
Error message shown in the system
Here is a solution
There is an error on the service order that’s why you are not able to confirm. Once the error gets resolved, you will be able to confirm.
Now you will be billing the service hours from the confirmation. However, you have kept the service order item category settings as "relevant for external billing". Check the configuration. This needs to be changed to NO billing.
The service confirmation transaction’s item category for this particular item needs to be set to Relevant for external billing.
This is the reason, you are getting error.