&1 &2 may not be changed

What causes this issue?

Master data and Customizing settings for characteristic '&V1&' are
being uploaded. The current value '&V2&' already exists.
According to the <DS:DE.FC_UPDMODE>update mode</> in the upload method,
any existing settings may not be modified.

System Response

&V1& &V2& will thus not be changed.

How to fix this error?

Make sure that you intended to retain the existing settings. If
possible, try to avoid putting objects like this in the upload file.

Error message extract from SAP system. Copyright SAP SE.