I am finding that in certain cases, io.ascii struggles to correctly ignore comment lines, and also the start of the data rows. Here is some particularly simple data that illustrates the problem:

# some header info
#F header info beginning with 'F'
1 2 3
4 5 6
7 8 9

If I run ascii.read(fname), I get
AttributeError: 'NoneType' object has no attribute 'group'

The workaround seems to be to set guess=False. Based on an email chain with @eteq the problem seems to be that the DAOPHOT reader specifically looks for the "#F..." pattern, and for some reason even though this is not a DAOPHOT output file, the reader fails when it tries to actually interpret that line. Erik told me to call the attention of @taldcroft to this issue.

My workaround for the time being is s imply to set guess=False:
ascii.read(fname, guess=False).
This does not bail when reaching the #F line, but now the first row of data is being ignored. My workaround for that latter problem is to manually set data_start=0, but this should probably be the default behavior.