Trying to add an accountant. When I click on Add user, Accountant, click on Next, system just shows a blank pop-up.

I'm here to help, jignesh-sam-gmai.

Here are a few possible reasons why you're getting a blank page when adding a user in QuickBooks Online:

• User is not logged in as the Master or Company Administrator.
• Browser-related issue. 

In QuickBooks Online, only the Master or Company Administrator can invite an accountant user. To verify your user status, you can go to the Gear icon (⚙), select Manage Users.

If you aren't an administrator user, you can request to have your permission change by your company's admin. Here's an article for the instructions: Add, delete, or change user access. You may also find this guide on user types and permissions helpful.

Otherwise, perform some basic troubleshooting steps to check if this is browser-related issue. To start, open your QuickBooks Online account in a private browser or incognito window. This mode prevents your browser from storing additional cache files that may be causing the blank page.

Here are the keyboard shortcuts: 

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

Next, go to the Gear > Manage users and try to invite the user. If you can add the accountant, our final step is to open your regular browser and clear its cache. Clearing the cache data helps to troubleshoot, increase the loading time of web pages and your computer's performance.

After clearing the cache, please make sure to close and re-open your browser. Alternatively, use a different supported browser.

If you need any additional assistance or other questions for QuickBooks Online, just leave a comment below. I'll get back to you as soon as I can. Thanks.