So, after redoing Temperature/precipitation maps for my planet because I didn't like how it turned out, I got an error when using the skcc.py code for Holdridge zones:

"Error: Invalid Holdridge category in output profile: Af"

Unfortunately, this type of error isn't listed in the ReadMe; could someone kindly tell me what that means?

The command code I used to run it is as follows:
py ./skcc.py --tempns="JulTemp.png" --tempnw="JanTemp.png" --precns="JulPrecip.png" --precnw="JanPrecip.png" --tempprof="actualTempProfile" --precprof="actualPrecProfile" --outprof="defaultOutputProfile" --mode=holdridge --outfile="output.png"