systemversion.plist on el capitan

I just get osx 10.11.1 el capitan but some of my important programs do not work on this version. I am trying to change systemversion.plist but my osx doesn't allow me. How can I do this? I need your helps guys.
Thank you.

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Clarification Request
(NT) I have to change fix this error! pls help me guys.
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This link may help

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