Limited validation, since the system is not set to 'production' status.

What causes this issue?

You want to delete the appropriation request.
The system status for appropriation requests is set to legacy data
transfer or test in Customizing in the status field.

System Response

When the system has one of these settings, it does not check the status
and assignment of variants to approval versions when an appropriation
request is deleted.

How to fix this error?

Check if you really want to delete the appropriation request.
Review the system controls for the status of appropriation requests.

Error message extract from SAP system. Copyright SAP SE.