QuickBooks Desktop Error Messages

The application trying to connect to QuickBooks is not supported while multiple instances of QuickBooks are running

How to troubleshoot multiple instances of QuickBooks are running error.


You cannot sync sales.


This error can happen for two reasons:

  1. If you use web connector 3.0, open the company file and sign in. Run the sync again.
  2. You have QuickBooks open twice on the same machine, but there is only one user. Close one of the QuickBooks by going to file and clicking exit. You can only sync with one file at a time.
  3. We recommend that users set up the web connector to run as admin, if QuickBooks is closed. This account ensures Connex has the proper permissions to create orders in QuickBooks. If Connex tries to login as admin and another user logs into QuickBooks as user B, then the sync will fail.

If a user logs into QuickBooks as admin, then the sync will resume. No sync timers are updated, unless the sync was successful.


Close QuickBooks Completely and Restart

If you have QuickBooks open twice, a window with the phrase secondary will appear. Close the other QuickBooks:

Change sign in info

Here are our suggestions:

  1. You can move Connex to another machine where no one logs into it, except Connex. If the machine uses remote desktop, ensure it's on 24/7. For more info on pairing another machine, read this guide.
  2. Login to QuickBooks as the admin user. If another user was selected, while the file is closed, then login as that user. 
  3. You can change the user that syncs, if the file is closed:
    1. In QuickBooks, go to edit and click preferences.
    2. Click integrated applications.
    3. Next to Connex, click properties.
    4. Change the user that logs, when the file is closed: