KeyError: 'SupportFraction' when running margin_cons.py

[GammaCarbon7]

When I ran margin_cons.py to get the consensus sequence, I encountered an error:
Traceback (most recent call last):
File "margin_cons.py", line 132, in
main()
File "margin_cons.py", line 129, in main
go(args)
File "margin_cons.py", line 82, in go
support = float(record.INFO['SupportFraction'])
KeyError: 'SupportFraction'
I don't know why. Could u please help me?