Order/WBS element cannot be statistic and plan integrated

What causes this issue?

You set the <LS>statistical</> and <LS>plan integrated</> indicators
for the order or WBS element.
Planned settlement is made in integrated planning. Additional account
assignments (statistical) are currently <LH>not</> included in planned
settlement.
Therefore, you are not able to use a statistical order or WBS element
with an obligatory,cost center (that has non-statistical postings) in
the plan.

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?

Either set the <LS>statistical</> or the <LS>plan integrated</>
indicator.

Error message extract from SAP system. Copyright SAP SE.