If you have an M-Tech USB Bluetooth adapter (like the common MT-BT4.0 or 5.0 models) and it's not working, follow these steps to get it running: Try "Plug and Play" first

This is tricky. MTech dongles are designed for Windows. Newer macOS versions (Catalina and newer) have removed support for many third-party Bluetooth dongles. Unless you find a specific open-source kext, assume it will not work.

. If you see "Bluetooth Radio" without a yellow exclamation mark, you’re good to go. The "CSR Harmony" Driver : Many older M-Tech dongles use the CSR8510 A10 chip . If Windows doesn't recognize it, you likely need the CSR Harmony Wireless Software Stack Manual Update via Device Manager Right-click the Start button and select Device Manager Locate the "Generic Bluetooth Adapter" or "Unknown Device." Right-click and select Update Driver Search automatically for drivers Third-Party Repositories