Quickbooks 2020 keeps crashing whenever I attempt to open or restore any files.

Hello Teasdale_St,

It's awesome that you've started to take on learning QuickBooks Desktop and that your sister-in-law has given you her courses to help you along. Great job with the troubleshooting you've done so far. I've got a few other suggestions for you that you can try as well.

The first thing I'd like to ensure is that you're opening the company file correctly. Since you're using a 2016 company file in a 2020 version, it's not simply that you're opening the file, it's that the file is begin upgraded to read in the newest version of the program. While sometimes it's as simple as opening the file, since you're having trouble, you may need to consider the additional prep work that can come with it. Check out the following article to learn what I mean by this: Upgrade your company files after switching to a new version of QuickBooks Desktop

Next, I've got another article that goes over troubleshooting steps of what you can do when having trouble opening the company file. Take a look at it here: What to do if you can't open your company file in QuickBooks Desktop

One other thing to consider when you're running QuickBooks Desktop 2020 is what .NET framework the computer is running on. There are known issues at this time with QuickBooks running on a 4.8 .NET framework on Windows 10 that causes issues such as the program crashing. I recommend checking with an IT professional or Microsoft support to find out what .NET framework your system is on and what can be done to get you on a previous .NET framework setup.

To speak with a QuickBooks Desktop tech support agent directly, check out the Intuit QuickBooks Desktop software support policies article. There, you can read about support hours, options, and what you should know before calling in.

I hope that helps! Have a great weekend.