This is a known issue with Logger pro version 3.8.6.2. Saving a file with the Vernier Emissions Spectrometer (
You may work around the issue by accessing the “rainbow” menu in the spectrometer setup dialog (accessed from the live readouts bar at the upper left of Logger Pro) and reset the mode to intensity. This allows further collection to take place using the opened file avoiding the erroneous calibration message. No calibration is actually needed.