DIY projects that were made with older versions of the LabQuest SDK (NGIO_lib) will not be able to communicate with a LabQuest or LabQuest Mini over USB if a newer USB device driver has been installed by another application. The newer USB device drivers were first distributed in May, 2016 by the following products:

• Logger Pro (version 3.11): https://www.vernier.com/support/updates/logger-pro/
• Logger Lite (version 1.9): https://www.vernier.com/products/software/logger-lite/
• LabVIEW: https://www.vernier.com/engineering/ni-labview/downloads/labquest/

In order to get you project working with the new driver, you can get the latest version of the LabQuest SDK from here:
https://www.vernier.com/downloads/software-development-kits/

You will then need to replace all occurrences of the SDK that are associated with your project with the files from the new version. The communication library is named NGIO_lib.dll, and is the probably the only file you really need to replace.