Error on \displaygrid.php on line 103

HI, I'm having this error when I pick to the menu that goes to my article that has a grid inside...

Call to a member function build() on a non-object in /....../...../.../.../plugins/content/displaygrid.php on line 103

some suggestions?

so, In my local copy too, there appear so may errors. using easyPHP 5.2.1.0

Thanks!
A.

WOOPs,
I had an error in my code, probably because a previous modification, so in the switch there were the two cases commented... Sorry now it's completely ok (I guess...)

it was like that...

switch($config->typejx){
				//case 'grid':$builder = new GridView($id, &$config);break;
				//case 'card':$builder = new CardView($id, &$config);
			}
            return $builder->build();
        }