Hello there, @jewholesale.
The error encountered when attempting to delete a category is often caused by browser-related issues. These issues may include cached data, cookies, or browser extensions interfering with the operation.
In the meantime, we can conduct some troubleshooting to identify whether the issue with deleting a category is linked to your browser.
Begin by logging out of your QuickBooks Online account and then logging back in. This helps refresh your session and can resolve temporary glitches. Once you're logged back in, try restarting your browser or refreshing the page to ensure the application fully reloads.
Alternatively, using private browser or incognito mode can improve the application's performance and can resolve the issue. Additionally, ensure your browser is updated for optimal compatibility with the platform.
These troubleshooting steps should resolve the issue of deleting a category. If the problem continues after trying them, feel free to comment below. We're here to help ensure you have a seamless experience in QBO.