Are you clicking on your game shortcut and nothing is happening? This is a common problem and its easily fixed!

Simply select and delete the following files:-

You are also advised to restart your computer, but your game should start as normal and your game will generate new fresh versions of those files.

If your game starts loading but crashes during the loading process then that is not due to the same issue and wont be fixed by the method above. The most common cause of that type of problem is unsupported custom content - most commonly an installed object requires an Expansion Pack that you do not have.