Hi, as "Master admin" user type, I should be able to add user in my QB. However, I received an Error Message instead. May I know what could have caused this problem?

Let's find out why you're getting an error when adding a user, sueng.

QuickBooks Online uses browser cache and cookies to run faster. This can block web pages from loading. To get rid of the error message, you can clear the browser's cache and cookies.

Once done, log into your QuickBooks account as the master admin. Then, follow the steps outlined below on how to add a user:

1. Go to Settings ⚙, then Manage users. If you can’t select this, you don’t have permission to manage other users. Contact an admin user for help.
2. Click Add user.
3. Select the user type you want to create. 
4. Enter your new user’s name and email address, then click Save.

Also, QuickBooks limits users depending on your subscription. Hence, you can check the table below to see the number of billable users you can add.

If you wish to increase your user limit, check out this link: Upgrade your QuickBooks Online subscription.

I've added this link for frequently asked questions about user access: Add and manage users in QuickBooks Online.

Let me know if there's anything else you need with QuickBooks by commenting below. I'm always around to help you.