What OS do you have on your Mac?
AutoCAD 2011 for Mac doesn't run on Mountain Lion (10.8.x)
In order to run correctly on Lion (10.7.2-10.7.5) and on Snow Leopard (10.6.x) you have to install all updates from here:
I upgarded those files from the link you gave but unfortunately the error still occours. I am using Lion. What should I do next????
Thanks a lot....!
You can try this:
but my advice is to move to 2012 or (better) 2013 release, if you can.