No exception can be maintained for characteristic "&1". See long text

What causes this issue?

You tried to maintain exceptions for a characteristic that has been
excluded from use as a segment-level characteristic or that is used as
a fixed characteristic in Profitability Analysis. No exceptions can be
maintained for this characteristic.

System Response

Under the current settings for segment-level characteristics, it is not
possible to call up exception maintenance for characteristic "&V1&".

How to fix this error?

Check the segment-level characteristics settings for characteristic "
&V1&" and make any necessary changes. You should be aware of the
effects (described in the Customizing documentation) that the
retrospective activation of segment-level characteristics can have on
how your reporting data is updated and analyzed.

Procedure for System Administrators

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.