Why can't place these propellant tanks above the others?

[InF3RNo]

Hello, I've been trying to create a large rocket like I've seen in videos or pictures, but I'm not able to place the propellant tanks above the others, any idea why? I can place one but not the others, they're red.

Edited July 7, 2013 by InF3RNo

[kahlzun]

It looks like you might have struts coming off the top of the bottom tanks, try moving them, it counts as a part..

[rryy]

Try placing it somewhere else first and then place it there.

[InF3RNo]

It looks like you might have struts coming off the top of the bottom tanks, try moving them, it counts as a part..

Oh right, the struts it was, I can't believe I didn't see it before.

Thanks,

InF3RNo.