"FAILED TO ESTIMATE IMAGE NOISE" error

[muhammad moosa]

hi everyone, iam trying to run calibrate.py and startracker.py using unittest.sh on images taken by canon eos rp. i have edited the exposure and apperture in calibrate.py accordingly. still, when i try to solve the image(i have only taken 1 image and set it as median image as well, kindly guide me about the use of median image and if i am doing it correctly). it gives me this error,

Extracting sources...
Failed to estimate the image noise.  Setting sigma=1.  Expect the worst.
No pixels were marked as significant.
  significance threshold = 1.12838
  max value in image = 0
Downsampling by 2...
No pixels were marked as significant.
  significance threshold = 1.12838
  max value in image = 0
Downsampling by 2...
No pixels were marked as significant.
  significance threshold = 1.12838
  max value in image = 0
Downsampling by 2...
No pixels were marked as significant.
  significance threshold = 1.12838
  max value in image = 0
Sorting brightness using FLUX and BACKGROUND columns failed; falling back to FLUX.