Grouping characteristics must be derived before acc. determination ref.

What causes this issue?

The sequence of rules is very important when creating derivation rules
for grouping characteristics and account assignment references. The
rules for deriving grouping characteristics must first be executed. Only
then can the rules for deriving account assignment references be
executed. The account assignment reference rules assume that the
grouping characteristics have already been determined.
You tried to change this sequence. This could cause errors in account
assignment reference determination.

System Response

The system does not allow you to move the rules.

How to fix this error?

Ensure that the rules for deriving grouping characteristics are executed
first. Only then can the rules for deriving account assignment
references be applied.

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.