Glad to see you here in the Community space, TerryinIW.
How are things coming along? I’d love to help in adding a new user in your QuickBooks Online.
Even if you deleted a user, you should be able to add them back. Let’s try performing some basic troubleshooting to fix the issue.
You can use a private window to start fresh. Here’s how:
• Press Ctrl + Shift + N keys on your keyboard (Google Chrome).
• Press Ctrl + Shift + P keys on your keyboard (Firefox or Internet Explorer).
• Press Control + Option + P keys on your keyboard (Safari).
Sometimes, switching to a different browser (Internet Explorer, Chrome, and Firefox) can help issues like this.
Now, try adding a new user. You can check out this article for the steps: https://quickbooks.intuit.com/community/Account-management/How-to-add-delete-or-change-a-user-s-acce....
If the private browsing session works, you’ll need to clear your browser’s cache to prevent unexpected behavior in the product. Make sure to remember your saved information, such as login IDs and passwords. Take a look at this article for reference: https://community.intuit.com/articles/1436727.
In case the same problem persists after performing the recommended steps, I’d suggest getting in touch with our Customer Care Team for further assistance. You can reach them through this article: https://community.intuit.com/articles/1145770.
Feel free to reach out to me if you need anything else. I’ll be around to help. Wishing you the best!