You just need to position your main character on the first stone and then move your teammates to solidify the second. Then move onto that one and etc. The bridge won't give out underneath you once you're on it, and then when you get across the puzzle is solved.

You have to position all your people on the stones intill the bridge peice turns from semi invisible to a solid bridge once you have all four parts of the bridge built walk across

without remembering the exact buttons to stand on, there's going to be 2 characters on the right, and one on the left. I did this a few days ago, so forgive me for my semi-poor memory but I believe the buttons on the right, are second one in and second one from the last (possibly third), and on the left, it's also either the second or third from the back. Then take your main character across the bridge leaving your others on the buttons. They'll follow once you're across the bridge and fulfill the next test which is... too easy to mess up lol

oblibionatm is right. You have to find a square on the sides of the chasm that make the blocks become visible. Once that happens change the character you are controlling to the next one and move them on the other side of the chasm to find the square that makes the block turn solid. Once the square is solid and you can walk on it it is ok to mover the characters off the squares they are on and find the next two squares to repeat the process. Just step on the squares and look at the bridge to see which block is visible, and look on the opposite side for the second switch. If the square to make the block visible isn't on one side it's on the other just look there for it. I can't remember the exact squares, but it shouldn't be hard to figure out.

1.This puzzle is not at all difficult, if you actually tried to solve it, it would be easy.

2.Make all your party characters stand on platforms surrounding the bridge, every time you make one piece appear, it only half appears, so you need to find the two switches that activate the first piece, then have your main character stand on it, it then becomes permanently in place, rinse, repeat.

www.gamefaqs.com/console/xbox360/file/950918/58305

hit ctrl + f and search for S1

www.gamefaqs.com/console/xbox360/file/950918/58281

This is a map of the puzzle and how to solve it step by step. Really simple. Check the FAQ section once in awhile if you're stuck.

Like everyone else said, but using the radial menu to acess hold position under advanced will let you move one character at a time, making it a lot easier.