A very frustrating thing that occurs between products that share financial data with QuickBooks is that the underlying QuickBooks.exe task may hang and not close out or end cleanly. This will cause the subsequent financial exchange to fail with messages similar to QuickBooks is already running. This can affect many products but I see it regularly with QuickBooks Desktop interacting with QuickBooks Point of Sale, and with Instant Accept payments integration.
You can try to run repair/reinstall of the software (QuickBooks and/or QuickBooks Point of Sale) but we have found that this may fix it temporarily only. The best way to deal with this right now is to disable any automated ways that financial exchange occurs, and to manually run the exchange as needed, AND to proactively look for and kill any hung QuickBooks.exe tasks prior to running the exchange. Yes, this is inconvenient but Intuit doesn’t really care anymore otherwise they would keep the QuickBooks POS product alive rather than killing off the product permanently on October 3, 2023.
First, close QuickBooks if it is open. Then go the following steps…
To find Task Manager, you have to right-click on an open space in the task bar of your screen and click Task Manager.
It will open up a list of tasks. You will need to scroll down the list alphabetically to find the QuickBooks task. Skip the top section listed Apps and scroll down through the second list, Background Processes.
When you locate QuickBooks in the background processes, right click on it to get a menu and click End Task.
Now you can bring up Point of Sale and try the financial exchange again. It should be successful.