Caution: the asset you want to retire is a group asset

What causes this issue?

The asset &V1& &V2& you entered is a group asset. You can only
post a retirement to a group asset, when all the assets assigned to
the group asset have been retired.

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?

Check the asset you entered.

Error message extract from SAP system. Copyright SAP SE.