Deletion is not possible since budget values already exist

What causes this issue?

You wanted to delete the assignment of measure &V1& to an investment
program position. However, budget values from program position
&V2&/&V3&/&V4& have already been distributed to measure &V1&.

System Response

Deletion rejected.

How to fix this error?

First return the distributed budget amounts from measure &V1& back to
program position &V2&/&V3&/&V4&.

Error message extract from SAP system. Copyright SAP SE.