new updates now cant build anything

Hi all,

i was playing this game happily until the 11th November when i think an update or something came out.

since i had trouble loading it, then another update which fixed the game crashing issue but now i cant build anything.

The game starts and i load sandbox mode but then when i select a building or coaster i move the mouse out onto the area and nothing happens.

i see no outline of the ride or path or building and i cant place any item.

anyone seen this?

any ideas?