The application requires that assembly Interop.QBFC7 Version 220.127.116.11 be installed in the Global Assembly Cache (GAC) first.By default, the installation section show below is hidden. Why? It’s because you only need to run them once. So make sure you click the Installation header to view the instructions and run through those steps first. The next time you export just go straight to the Exporting Instructions. Hope this helps!
One of the most common mistakes new users make when doing an mHelpDesk to Quickbooks export is skipping over the installation steps. You may get the error below: