Investment support &2: Support dep. area & cannot be deleted

What causes this issue?

Depreciation area &v1& is defined as investment support area for
investment support measure &v2&. Since the APC is always reduced for
the investment support measure in the investment support depreciation
area, you cannot delete depreciation area &V1& from the list of
depreciation areas for APC reduction.

System Response

Depreciation area &v1& is not deleted.

How to fix this error?

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

Error message extract from SAP system. Copyright SAP SE.