I tried running a "Sales by Product/Summary" report, but it isn't working. Does anyone know how to fix this problem?

Welcome to QuickBooks, mitchg-martin.

Are you trying to search for the report and you're unable to find it? 

We'll want to make sure that we've provided the correct name of the report so it shows up on your QuickBooks Online (QBO) account. To search the report, you can follow these steps.

1. Click Reports on the left menu.
2. On the search bar, type Sales by Product/Service Summary report. 
3. Under the Report period field, click the drop-down arrow and choose the date.
4. Click Run report.

However, if you've searched for the correct name but report isn't showing, let's try a few steps to resolve this issue. There are times that your browser is full of frequently-accessed page resources, causing QuickBooks Online (QBO) to act unusual behavior. 

You can log in to your QBO account using a private browser to rule out cache-related issues. Here are the keyboard shortcuts:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Safari: Command + Option + P

If it works, clear your browser's cache to speed up the loading process of the QBO website and for the system to start fresh. You can also try switching to a different browser to see if it works.

To make sure that you have all the information you need, learn to export reports to Excel. Please check out this article for your reference: Export Your Reports To Excel From QuickBooks Online.

You can always touch base with us anytime if you need further assistance. I'm always here to help.