This is the steps which cause the error:
On a report, block one or more lines. Then without leaving the area, or clicking on any other line issue the Block>Move>Append. You get an error.
If you block one or more items, click off the blocked lines then give the append it moves the block to the line you clicked on, not to the bottom.
I’m still on version 2.04 but should that make a difference? I didn’t update to 2.05 because of the printing problem, but I will.