I am trying to add new product catogaries and the system is telling me that they already exist, however they are not displaying on my catogory list at all. what to do?

I'll make sure you can add new product categories in QuickBooks Online (QBO). 

We can perform some troubleshooting steps to fix this. There are times when the browser is full of frequently accessed page resources, which causes some errors or unusual responses. 

Let's start accessing your account using a different or private browser. You can use either of these shortcut keys:

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

Once logged in, try to add the product again. If it works, I recommend clearing your browser's cache. Doing so will remove the historical data and access QuickBooks with a clean slate. You can also switch to a different supported browser.

I've added these article to learn more about bringing in your data as well as managing products and services:

• Common questions about importing data
• Add stock products
• Group products and services into different categories

Come back to this post if you have other concerns or follow-up questions about products and services.  I'll be right here to help. 

We appreciate you for coming back.

Thank you very much! I appreciate you taking the time to let us know that you've figured it out. I also commend you for following the suggestions and utilizing all of your resources to arrive at the solution you have now.

As always, the Community is brimming with professionals who are knowledgeable in every aspect of QuickBooks, so please don't hesitate to contact us here if you have any questions. We're always happy to assist you on your way to victory. I wish you and your company continued success!