> Does anyone know why one would get this error?
The XISF files that cause the error
*** Invalid block position: attachment:8192:140332416 (line_4 offset=208)
*** Error: The XISF file contains no readable images.
are corrupted for some reason. These files only contain the metadata (i.e. the XISF header) and no image data. I cannot imagine that these files are generated by PixInsight directly. Did you modify them somehow?
Irrespective of the corrupted files I wonder why you wanted to integrate calibrated, debayered light frames. This is note useful as the images are not yet registered. The workflow for preprocessing the light frames should be:
ImageCalibration -> (optional: CosmeticCorrection) -> Debayer -> StarAlignment -> ImageIntegration
> ALSO, Ido I have the correct settings, for integrating 48 image and 20 dark files?
No, the settings are not correct.
For the integration of preprocessed light frames use these settings: Call ImageIntegration and reset the process. Under Pixel Rejection (1) set 'Percentile clipping' for 3 to 6 images, or 'Winsorized Sigma Clipping' for 8 to 10 images or Linear Fit Clipping for at least 15 images. Under Pixel Rejection (2) the default parameter are meant as a starting point. These values shall be adjusted by the user so that artifacts caused by aeroplanes, satellites, meteors etc. are fully rejected at the least percentage of rejected pixels.
For the integration of calibration frames use the settings given here for the particular sort of calibration frames:
https://www.pixinsight.com/tutorials/master-frames/The preferred settings are the same for bias, dark and flat-dark frames (see chapter "Bias and Dark Integration"), but different for the integration of calibrated flat frames (see chapter "Master Flat Generation (II)").
Bernd