Welcome to the forum.
With previous versions it has been possible to some extent to
do what you want. Not advisable but possible.
With this version that is not possible. You might experiment
using the various methods and you will be able to open the RH7
project in earlier versions. Wait until you try to save your work
though.
There's a lot more in RH7 so you might all want to consider
upgrading. At one time the upgrade was only $80 but that offer
finished. You might still find it from some vendors.
Help others by clicking Correct Answer if the question is answered. Found the answer elsewhere? Share it here. "Upvote" is for useful posts.