error? inconsistent dedent

[Holger Jannsen]

Couldn't understand following error:

C:\myPython>installation16.py -x -d test
inconsistent dedent
  File "C:\myPython\installation16.py", line 619
    opts, args = getopt.getopt(sys.argv[1:], 'x')
                                        ^
SyntaxError: invalid token


What does 'inconsistent dedent' mean? 
Why does that error occur?

Thanx,
Holger