That's strange. Did you uninstall the previous version when installing the r86 ?
By the way, r87 has been released since it should even work better.
I've just tried opening the capx and got no error, there's an issue on your end.
Make sure to uninstall all copies of C2 and install the very latest release r87.
Install it, download the capx again, open it.
If you're still obtaining check failures and errors, be sure to make screenshots/read the content of the error messages as it gives informations on what may go wrong.
Anyway, Layout :
<center><img src="http://dl.dropbox.com/u/36472942/construct/forumhelp/RandomMath_Layout.JPG" border="0"></center>
Event sheet + objects :
<center><img src="http://dl.dropbox.com/u/36472942/construct/forumhelp/RandomMath_Events_objects.JPG" border="0"></center>
Group "MakeQuestion" expanded :
<center><img src="http://dl.dropbox.com/u/36472942/construct/forumhelp/RandomMaths_GroupQuestion.JPG" border="0"></center>