Selection overlaps with loop lines

What causes this issue?

You have chosen either the <LS>Select block end</> function, in order
to extend a block, or a box where all the screen elements are selected.
This block contains parts which belong to a loop block and some which
do not. This kind of overlapping is not allowed.

How to fix this error?

The block can either contain no loop elements or it must lie completely
within the first loop block, but not in any loop repetition lines.
If you want to move or delete an entire loop area, place the cursor in
the loop area and select the <LS>Loop</> function.
If you want to move or delete a box containing a loop area, you must
move the box and the loop area separately. You can process a box on its
own (i.e. without the elements it contains) by placing the cursor on
any character of the box edge and choosing the <LS>Graphical element</>
function.

Error message extract from SAP system. Copyright SAP SE.