"An exception has occurred" says the pop-up. Did it three times don't know why. But it's a fun game :) Some things are bugging me though, when i hover over a poster and it enlarges it, i automatically want to go for the enlarged image to place the poster on the billboard, but if i do it will deselect it, its not intuitive. Two things to try, enlarge the poster in a way that some part of it will remain under the cursor or duplicate the image and display a clone of it enlarged in the middle of the screen. Also with the posters, when i grab a poster, make the un selected ones slightly transparent so i can see behind them. The other ting is, when i misplace a poster, say, out of bounds of the billboard don't release the poster from my hands, simply indicate that it is not a valid placement and i can try again. The concept and the art is good and i really enjoy these types of games ^^
About that error, i'm running Chrome (67.0.3396.99) on a W10 machine