Unable to define screen element in loop block

What causes this issue?

You attempted to create a screen field which is supposed to start at
the position marked by the cursor. However, although it is in a free
space, the cursor is inside a loop block.
You cannot create any type of screen field in a loop block for
subscreens, pushbuttons, boxes and controls.

How to fix this error?

The cursor position which defines the top left corner of the screen
field must be outside any loop blocks or loop repetition blocks.

Error message extract from SAP system. Copyright SAP SE.