Diagnosis
You want to define a loop block. This is a rectangle where the size isdetermined by the current cursor position and the element you choose asthe start of the loop block.
The rectangle contains part of a graphical element (e.g. radio button,checkbox), but not the other part. For example, it may contain thecheckbox, but not its associated text.

System Response
Graphical elements must lie either completely within a loop block ornot at all.
The system cannot create the loop block and therefore does not executethe operation.

Procedure
Set the cursor, so that the system can create a loop block.