I am unable to open employees tab on my iMac

Hello accounts519,

Let's make sure you've enabled third-party cookies on your browser to be able to access the Employees tab in QuickBooks Online. Here's how to:

Safari

1. Go to the Safari menu and select Preferences.
2. Click on the Privacy tab and under the Cookies and website data, ensure the Block all cookies and the Prevent cross-site tracking option is not selected.

Chrome

1. Click on Settings menu.
2. Scroll down to the bottom of the settings screen and click Show advanced settings.
3. Under Privacy, click the Content Settings button.
4. Under the Cookies section, endure the Block third-party cookies and site data option is not ticked. 

Then, close out your browser and re-launch it once more and access your Employees tab. 

Also, you can check the articles below to learn more about the recommended browser and how to clear cache on your browses:

• System requirements for QuickBooks Online, Accountant, Payroll, and QuickBooks Self Employed
• Clear cache and cookies to fix issues when using QuickBooks Online

You can always drop a comment below if you need more help with QuickBooks Online Payroll. The Community is here to help you. Have a nice day!