Indicator allowing interval values cannot be deleted

What causes this issue?

You want to delete the indicator "Interval values allowed", so that
interval values can no longer be assigned to the characteristic.
The characteristic has already been used. The system check of values
already assigned has found at least one case where an interval value
was assigned to the characteristic. This contradicts what you want to
do with the indicator.

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?

Undo your change.
Before you delete the indicator again, first check all values assigned
to the characteristic and delete the intervals if appropriate.
To see a list of all the places where the characteristic is used,
choose <LS>Environment -> Where-used list</> from the characteristics
menu.

Error message extract from SAP system. Copyright SAP SE.