Did they delivry the wrong cubase version?

i did not uninstall the cubase 6 i just installed cubase 7 version over it in same folder and downloading the 7.5 right now and will do the same is it correct? Becuse when i open cubase 6 now its crashing when i press the “E” button to see the vst plugins in the mixer, I dont need cubase 6 anymore anyway i just wondering if i do it right.