Either enter a percentage, an equivalence number, or an amount

What causes this issue?

You have filled at least two of the fields "Percentage", "Equivalence
number" and "Amount" in a settlement rule.

How to fix this error?

Enter either a percentage, an equivalence number or an amount. If you
want to combine the amount settlement with settlement by percentage
value or equivalence numbers, then enter the amount rules separately
each time.
If you receive this message outside of settlement rule maintenance, you
must first go to settlement rule maintenance to check the individual
rules.

Error message extract from SAP system. Copyright SAP SE.