Why does the message 'Failed to detect CEI-xxx hardware' appear when I run the CEI-x20 'Test Config' application with a CEI-520A installed?

The CEI-520A requires CEI-x20-SW version 3.80 or higher. If version 3.80 or higher is already installed, contact GE Fanuc Intelligent Platforms technical support (avionics-support@gefanuc.com). Otherwise, browse to the CEI-520/520A  page on our website for the latest downloadable CEI-x20-SW distribution and uninstallation/installation instructions.