Hi.

For some reason my game wont load when using an older flash version than 11.8

I cant find any prerequirements for flashplayer stated on this webpage. I have searched the adobe site and there I can only see that at least 11.1 is needed for the stage3D etc.

What parts of my project could be the reason that my away3d game won’t load on versions before 11.8? Im using FD, Flex project to build my game.

What enviropment are you using?

Here is the guide on how to do what you want for flash builder:
http://sourceforge.net/adobe/flexsdk/wiki/Targeting Flash Player 10/

Edit: it seems that this forum does not support urls with whitespaces so just copy\paste the link above