Choose a valid LIFO method

What causes this issue?

You have entered a version which is not defined in Customizing and to
which no method is assigned either. The method entered is therefore
definitive for the procedure.

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?

In general, there is no need to do anything. If you want the version
entered to always reference the method entered, you can create a link
for this in Customizing.

Error message extract from SAP system. Copyright SAP SE.