You are very likely starting the calibration Wizard from the wrong platform tab in the platform file (when multiple platforms are installed, each one will create a tab in the platform file)
1. Start Test Manager and open your platform file (if multiple files are present, open the one you commonly use for all testing)
2. Make sure that you start the calibration wizard from the platform tab that matches your actual hardware setup. E.g. you have an A304 hardware setup, but the software of all other platforms have also been installed. In the above picture, we start the calibration wizard from the A304 platform. Note that other platforms are also present in the above picture. Those tabs are crossed out to underline the point that calibration wizard should only be started from the appropriate platform.