A strange problem in smart form?

Hi,

I met a strange problem in my smart form. When I click "Check" button in each window of each page, system said "Window (my window name) does not fit onto page(height)". Even I create a new page and a new window in it, it still said this error when I click "Check" button in the new window.

I have tried to enlarge or reduce the window's size, but this error still occured. But I can activate the form correctly. And there is a syntax error in the generated program:

FORM %EV2.

LOOP AT INTO .

CALL FUNCTION 'SSFCOMP_TABLE_ROW_BEGIN'

EXPORTING I_LINE_TYPE = 'LINE2'

You can see there's an error in loop statement.

Could you tell me the reason and how to solve it?

Thanks a lot!