Okay trying to stack lets say 5 marines on a 1x1 square, I tried using marine sprites moving them than enabling doodad for the marine and make another marine and doing the same thing
but then i got an error any help?

The enabling of the terran marine needs to happen outside of the player's vision, or else the game will crash. I'm not sure of exactly what combination of enabling//disabling allows the marines to stack, but I do know you can't have a marine selected during the process, or have the screen position over the marine being enabled, otherwise a crash of SC results.

If you'd like to consider a non-sprite version, you can do it with a powerup, as done in Time Defense.

Okay I did it but i have a marine that is "disabled" and can't move and one that can move freely ( No Crash )

Jaff: what do you mean a power up?

Here is what Jaff was referring to: http://www.staredit.net/topic/8261/

Basically, you create a powerup where a ground unit is, and it allows those units to ignore their collision boxes with each other. I believe you need to have the powerups be there for at least 1 trigger cycle, which is why in those pictures there is a wait 0 milliseconds actions; to ensure that the powerups created lasted at least 1 trigger cycle before being removed.

Um, and by using the move order can these units be controlled by a player without massive clicking?

I don't see why not, try it out

lol well im trying to have it where a unit is pretty much permanently stacked and can be moved. Will this work?
Or will I have to use sprites?

In this post, http://www.staredit.net/169300/, it says the units unstack when you move them with a trigger. Other than that, I don't see why not.

Don't nail me on this, but I was always thinking that when you displace units with a powerup and they get stacked in the process (just like unburrowing or any other method) that they still have their collision box intact and try to unstack as soon as the terrain allows it. And that they (mostly) ignore orders in that state.

And for the stacking im trying to have 2 marines in unison but this isnt working as they always try to get out of a 1x1 square

Are you disabling/enabling the marines one by one?
Since 1 is stacking you obviously have the method down, but be aware that changing the doodad state can only be applied to one unit at the time and it will always be the same. So you have to use 1 location per marine or use some kind of cycling system that gives to other players.

Here, you can take a look at this map. It does exactly what you want it to do with sprites, although, like I said, I don't know exactly how; I haven't tried doing this for a long time.

I have no idea what to do after i disable the units, they are just sitting there in being cloaked/disabled. And if i move them all to 1 location and enable them again they form into rockish things

enable them away from the player's vision. Once enabled they will have lost their collision box.