VS12 crashes at burn step

[Black Lab]

You can turn off SmartRender, but all your clips will be re-rendered, even the MPEG-2 clips that may already be DVD compliant. As long as you are happy with the quality that's all that matters.

[2Dogs]

By the way, has anyone tried the Video Optimizer in Share>Create Video in VS 12?
Is it not equivalent to Smart Render? I tried it and it works but no saving in time

It is indeed the same as Smart Render. As far as I can tell, it simply gives you a visual indication of which parts of your project will be smart rendered, and which will be re-encoded - the former being the green sections, and the latter the red ones.

I find that Smart Render will still occur if you retain the video properties but change the audio properties - for example converting LPCM to Dolby or vice-versa.

Perhaps the reason it doesn't appear to save any time is that you are already, perhaps unwittingly, using Smart Render. That would be the case if you selected "Same as First Video Clip" for the output file properties in the "Share>Create VideoFile" step, or even "Same as Project Settings" if the project properties had automatically been set to match the first inserted video.

You could easily confirm this by deliberately disabling Smart Render, by clicking on the "Options..." button in the "Create Video File" dialogue box, and unchecking the "Perform Smart Render" box.

Believe me, Smart Render saves time.