I believe I found I bug.

The 'next' statement for loop control will not work in 2D Input but it does in Code Edit Region.

From the documentation on 'next', I copied the following code into a 2D input in a document. 

Running it results in Error, invalid expression for eval; id=54 which is a missing help page.

for i to 4 do
    for j to 4 do
       print([i, j]);
         if i = j then next i;
        end if;
   end do;
end do

However 'next' without a following integer/name works fine in both 2D Input and Code Edit Region.

So is there only a subset of Maple code that will work in 2D Input?