VirtualBox cloned vdi starts but no display

I have virtualbox, host win7 and guest ubuntu 14.0.4 I created a fixed sized vm. I cloned the fixed sized vm to a standard sized vm(dynamic). It worked perfect, just a message referring to low disk space. when I restarted the computer and run dynamic vm, it starts but with no display. Could it be in coection with its settings? because I cloned it from a fixed size vm. thanks ahead Kian William