Hi Yves, calibration of your data is done while the files are loaded, so there is no need to save the calibrated frames. ( but I always do for future projects, I don’t keep the calibration frames..)
If you have loaded your lights and master calibration files, you will want to check the quality of your calibration by setting the image viewer to the l-calibrated mode instead of linear mode ?
If you then click on one of your lights in the file list, it is loaded and calibration is applied, so you’ll see the calibrated image in the image viewer.
Personally, I always verify calibration before starting with 3) star analysis.