Bests & Worsts Reviews from Amazon

I am a CPA. I have clients with versions back to 2007. They send me files, I make corrections to their entries and send them corrected files for their future use. I purchased QB 2018 in early October because a client upgraded before they sent their information to me. As soon as I downloaded QB 2018, it made all the other versions of QuickBooks and QB 2018 inaccessible. I called support and they got them running (really another story completely, but all the versions were working for a while). Now 30 days later I cannot access any of the QB programs from 2009 to 2018. I have to call them again. I wish I had never purchased QB 2018. I need to do some work and can't. After reading some of the threads on the internet, I guess I am lucky I got this far. Some people were having the same problems back in 2012 that I am having now.