New
#11
What security software are you running, and have you tried just using Windows 7 with the latest service pack if you still have that OS for your computer handy. There are going to be issues with older software and Windows 10 going forward, unless Intuit comes up with a Service Pack for their older versions. Windows 10 AE is still new, so Intuit may still be working on fixes. As for the person helping you, it is good that they spent time trying to help. I had two people from Symantec that spent hours on the phone helping to get their SEC (Symantec End Point Cloud) working on my Macbook, because of an issue on their end when I tried to use the Encryption for locking down my Macbook. We just have to keep filing tickets and working with them.
You should not have to disable Defender or the Firewall. Not much that you can do. This problem dates back to when AE for Windows 10 came out and appears that Intuit does not care about fixing the older version of Quicken that is no longer supported. Consider it forced software obsolescence, which big companies like Intuit are very good at. quicken 2016 will not run on windows 10 after Anniversary update | Quicken Customer Community
It's my observation that any "planned obsolence" is a simple matter of economics, if a product has been discontinued, no longer being sold, there is no more income from sales that can be use to pay programmers for writing new/updated software.