How to fix: "Unable to cast COM object of type System.__ComObject..."
This guide is provided by Conductor, the service that powers the QuickBooks Desktop integration for many business tools, including the one that sent you here.
If a Conductor error message directed you to this page, it’s because we encountered the following error when attempting to connect to QuickBooks Desktop on your computer:
Unable to cast COM object of type 'System.__ComObject' to interface type
'Interop.QBXMLRP2.RequestProcessor2'. This operation failed because the
QueryInterface call on the COM component for the interface with IID
'{8DB91B17-D5A2-41DB-80A7-CC6F1E449A05}' failed due to the following error:
No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).
Solution
Complete the following steps to re-register the QuickBooks Desktop components to resolve this issue:
Close QuickBooks Desktop
Completely close QuickBooks Desktop before proceeding.
Open the Windows PowerShell as an administrator
Using Windows search (often in the bottom-left corner of your screen), type “cmd”, right-click on the “Command Prompt” result, and select “Run as administrator”.
Run the command to re-register QuickBooks components
In the PowerShell window, paste the following command and press Enter:
regsvr32 "C:\Program Files (x86)\Common Files\Intuit\QuickBooks\QBXMLRP2.dll"
Restart your computer
If the command was successful, restart your computer to ensure the changes take effect. After restarting, try connecting to QuickBooks Desktop again.
If you’re still encountering the same error after following these steps, please email us at support@conductor.is.