Calculation key &2 for depreciation key &1 not explicitly straight-line

What causes this issue?

This report changes assets' depreciation keys from the
declining-balance method to the straight-line method.
It is not clear, however, whether the new depreciation key that you
have entered uses a straight-line depreciation method.

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?

You must only use this depreciation key if you are sure that the
calculation key uses a straight-line method.

Error message extract from SAP system. Copyright SAP SE.