Hi,
Just trying to explain the error. See the Page has windows (Window height and width visible in the layout editor and also when you see the windows node). Now the thumb rule is
Windows cannot be wider or longer than pages.
The templates resides in a particular window. Again the rule is Template (in your case 7 cm ) or tables width cannot be bigger that windows width as it has to fit in the window.
Finally the lines length and height wise in the template cannot be bigger than the template as then it would not fit into it. So, going by this understanding please increase your window width so that its more or equal to template width but be careful that it should not exceed the page width.
Hope this helps to get an idea of what's gone wrong.
Cheers,
Arindam