[modeller_usage] Error with the Mutate script

Dear Sir,

I am trying to mutate a residue THR61. Using the script provided on the website, I am getting following error:

rayarjun$ python /usr/bin/mutate.py 1AV1.pdb 61 THR A > 1AV1.log File "/usr/bin/mutate.py", line 36 def refine(atmsel): ^ IndentationError: unindent does not match any outer indentation level

Could you kindly help identifying the cause of it? Regards

Arjun