No sort defined in basic list

What causes this issue?

You attempted to go to the <LS>Control Levels</> screen, but no sort
has been defined in the basic list. Therefore, the screen is
meaningless.

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?

On the <LS>Basic List Line Structure</> screen, define the fields you
want to sort by. Then, you can branch to the <LS>Control Levels</>
screen.

Error message extract from SAP system. Copyright SAP SE.