WRP1 - Message no. WG030 No supply source can be found for external req. no. xxxxxx, material no. xxxxxxx

Hello, I have the following problen when run material in WRP1 with Supply source = 2 ( Stock transfer ), Someone know how to solve the issue?

Thnaks a lot.

No supply source can be found for external req. no. U927115456, material no. 000000000000000309

Message no. WG030

Diagnosis

The source of supply could not be determined using the transmitted data.

System Response

The order item cannot be identified and is not posted.

Procedure

Maintain a source of supply for this material.