If a quiz or project will not open and takes you back to the start page, there is a reason. It indicates that there is a quiz already open. the quiz is trying to open another one.
Check your tabs to see that you have more than one quiz opened. To resolve this, minimize the current window to reveal the open window behind the one that you are working in. Closeout all other windows/tabs and try it again. If the quiz still will not open, minimize your screen and you will more than likely see that there is already a quiz opened.
To see this, open the video for a demonstration.