Purchasing document & not yet released

What causes this issue?

The purchasing document is subject to a <GL:release_strategy>release
strategy</>. The goods receipt cannot be entered until Purchasing has
released (approved) the document.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Contact the person responsible in Purchasing in order to have the
purchasing document released.
You can view the release strategy in the header data of the purchasing
document.

Error message extract from SAP system. Copyright SAP SE.