I have installed Autocad 2013 on a Macboobok with OS X 10.8.5. The application starts but after displaying the splash screen briefly it will shut down. I have attempted the suggested fix of removing files from the Flexnet folder but it did not resolve the problem. This is a new installation. No versions of Autocad were previously installed. Autocad LT is now installed with a trial version temporarily and it does open. What would cause this issue? I have a license for LT and I can not use it. How can this be resolved?