Can't open QuickBooks-QuickBooks Pro 2016

Let's perform some troubleshooting steps to get your QuickBooks working, Mark O.

There could be several possible causes why you get an error when you try to open QuickBooks Desktop. Among these are:

• Your company name may be too long
• You may have a damaged or missing QBWUSER.INI file
• You may have corruption on your hard drive
• Your program files or QuickBooks Desktop installation may be damaged
• You may have a damaged Windows operating system

We can run the QuickBooks Tool Hub to help fix common errors.  For the best experience, we recommend using Tool Hub on Windows 10, 64-bit. Here's how: 

1. Close QuickBooks.
2. We recommend you download the most recent version (1.4.0.0) of the QuickBooks Tool Hub. Save the file somewhere you can easily find it (like your Downloads folder or your Windows desktop). Note: If you've already installed Tool Hub before, you can find out which version you have. Select the Home tab.  The version will be displayed on the bottom right or you can select About to view the version.
3. Open the file you downloaded (QuickBooksToolHub.exe).
4. Follow the on-screen steps to install and agree to the terms and conditions.
5. When the installation finishes, double-click the icon on your Windows desktop to open the tool hub.

The Quick Fix will shut down any open background processes QuickBooks uses. Then, it'll run a quick repair on your program. Let me show you how: 

1. In the QuickBooks Tool Hub, select Program Problems.
2. Select Quick Fix my Program.
3. Start QuickBooks Desktop and open your data file.

For other troubleshooting solutions, you can check out these articles:

• Solutions for when QuickBooks has stopped working
• QuickBooks Desktop doesn't start or won't open

I'd like to know how you get on after trying the steps, as I want to ensure this is resolved for you. Just reply to this post and I'll get back to you. Keep safe always.