Currently using Pro 2004. Can I update to Pro 2018?

I recommend you ask Intuit to update that file for you.

Otherwise, the first interim update really should be to QB 2007.

The datafile you have is and old-style flat table. It was changed to a true relational database in QB 2007 (released in 2006). Intuit has a three-year cycle. That means QB 2004-2007-2010-2012 (this is the final "old style program")-2015-2018.

That's  why you should have Intuit do it.

How do you have Intuit do it?

Hello, @Bth109.

You’ll have to contact our Customer Support to get help with your company file. The QuickBooks Data Services team has the tools that can update your file in a safe and secure environment. 

You can arrange a callback to talk to them. Follow the steps below:

1. From your QuickBooks Desktop account, click the Help menu at the top. 
2. Select QuickBooks Desktop Help. On the Have a Question? window that appears, click the Contact Us button at the bottom part of the page. 
3. Provide some insight with this concern in the Tell us more about your question box. Then, hit the Search button. 
4. You'll now be provided a few support options. 
5. Select Talk to a Specialist to arrange a callback from a support agent. Or Message an Agent to chat with them directly. 

Here's the contact the QuickBooks Desktop Customer Support Team article for more information about this. 

I'm always here if you need anything else with your account. Let me know in the comment section below.