Hey, I don’t know if this will help but there is quite a bit of information in this thread:
including people talking about issues upgrading.
There are also several other more specific topics started by individual people having issues with the upgrade. Since I don’t have a specific fix for this, until someone comes along who may know something useful to your situation, you may want to try the thread I linked, and also, when I put rytm 1.7 into the search I got a ton of results.
Best luck with your upgrade!