sqrt of invalid value

[jochenstahn]

I got the following message for various data reduction runs:

(venv) mpc3241:artur_braun stahn$ python -m eos  -f 8806 -o test
# ######## eos - data reduction for Amor ########
# normalisation is unity
# input:
#     amor2025n008806.hdf
/Users/stahn/software/amor/eos/projection.py:214: RuntimeWarning: invalid value encountered in sqrt
  self.data.err = self.data.ref * np.sqrt( 1./(self.data.I+.1) + 1./(self.data.norm+0.1) )
# output:
#     ./test.Rqz.ort

Looking at the formula, there should not be a zero or negative argument possible. Maybe a None?