You have yet to tell me what action you were performing when you got the error. The style is modified from it's original version, so I don't know what code changes have been made.
Provide me with more detailed information, and I would be happy to try and help you out. Do you get this error when you upload the style and make no changes to it? Installed any modifications lately where you may have incorrectly added code to a template on that style?
Here is what comes up on Google search results
http://www.google.com/search?sourcei...t+supported%2e
I didn't go through the results, but it seems like an apache error.