Welcome to the forum.
Look on my site instead! :-)
The answer is no. Once you upgrade to RH7, the code is
changed and the project will not work in X5. The old tricks will
not work this time. You will find you can open a topic using those
but wait until you try to save. That's why you cannot work with
both versions.
See the topics on RH7 and Using RH7 on my site.
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