Why does qb Inline sometimes hangs when I try to open a client ?
Thanks for dropping by here in the Community, @mventer.
I'm here to help you get rid of this error that you received so you can open your client's account.
The error message: You may only work on one company at a time appears if you press Ctrl+N, open a new tab within the browser or choose File and then New from within the browser to start the second company.
When the new window opens it shares all session information with the original window, including authentication information. For this reason, you can only be in one company at a time if you launch the additional window this way.
To get around this error you will need to use a different browser:
Stay logged into the original company.
On the Windows desktop, click the Start menu in the lower-left.
Select a different browser then you are currently using (for example, if you have QBO currently open in Google Chrome, open the second company using FireFox or Microsoft Edge).
Log into your client's company.
To give you more tips on what are the browsers that work best with QBO and on how to fix performance issues, please see these links: