The warning "142 WL calibration failed" is displayed when a level of light source is not enough at wavelength calibration or calibration cannot be executed because wavelength difference is out of calibration range.
There are three suggestions listed below.
After restarting, please try the wavelength calibration again.
With high performance capabilities and a wavelength resolution of 10 picometer or less, the AQ6319 is designed for advanced research and development applications. With a wavelength range or 600 to 1700 nm this OSA offers an excellent combination of wavelength range and resolution.