Deleting is not possible (see long text)

What causes this issue?

You cannot delete asset &V1&, sub-number &V2&, and you cannot mark it
for deletion. The asset is still active, for one of these reasons:
The asset still has values, because it has not been completely retired.
The asset does not have values, but the capitalization date was set
manually in the asset master record.
The system only allows deletion of inactive assets (assets with no
postings) or assets that are deactivated.

How to fix this error?

Assets that have values must be completely retired before they can be
deleted.
If there is no posting to the asset, you must manually remove the
capitalization date using the <LS>Change asset</> function. You can use
the <LS>Change old asset</> function to set a deactivation date for an
asset transferred from a previous system that does not have postings.

Error message extract from SAP system. Copyright SAP SE.