&2 resources selected for operation &1. Proposal: &3

What causes this issue?

You want to plan or release operation &V1&.

System Response

The current resource of this operation is not allowed.
The system has selected &V2& allowed resources. Using function
'Resource selection' to select as resource. The first resource
contained in the list is resource &V3&.

How to fix this error?

Change the resource in operation &V1&.

Error message extract from SAP system. Copyright SAP SE.