Steps described here seems to be ok.
Can you do one last try? Don't scale the model at all and just move the camera. Tell me if it is still the same outcome after that.

@LegoPilot
It crashed? Are you rendering on CPU/GPU? Which CPU/GPU do you have? How much RAM?
Maybe you used up too much memory and your graphics driver crashed (happened to me quite often with 2.78a)? And be asured that HDRs eats up a LOT of memory (especially on GPU)!

Not scaling the model indeed helped, it looks much better now.
Old one: http://i.imgur.com/7z2rU7y.png

New one: http://i.imgur.com/zrZ6tyF.png

I guess we can safely say it is indeed the scaling that is the problem. Which is annoying, because it was much bigger than the camera, and difficult to fit in the frame. Thanks for the help!

@NGCHunter2: I am rendering on CPU, I think. Normally, it runs just fine, this was the first time it stopped working. My laptop is pretty capable of dealing with the renders, so I think it had something to do with the script. Last run went as smooth as it gets, except for the lag after running the script.

Good to know. I don't know how familiar you are with Blender but you can easily set the camera location and oriantation by using the Lock "Camera to View" feature. You can find this tickbox on the right view of the viewport in the right hand side column. The camera will follow.

It has to be CPU. GPU doesn't render the round edge shader.

I also just tried to recreate what Lego Pilot did using Blender 2.78c & Template 1.9.8, using the same steps (open template > delete bricks > import > scale/move model > select HDR > run script > switch Device from CPU to GPU > start render. Unfortunately it too is still generating with the cloudy shader effect. Scrubs, you mentioned that the GPU doesn't render the round edge shader, was that not the appropriate way to make sure it rendered with GPU rather than CPU? Here's a screenshot: http://imgur.com/AxVnt3Y.png

Just for testing I've also tried rendering with the "Open Shading Language" box checked and unchecked::
Checked: http://imgur.com/fqBY8wy.png
Unchecked: http://imgur.com/bLcvqSx.png

For moving the camera instead of resizing the model, I found that using the steps (import collada > move camera > open HDR > run script) resulted in the python script failing to run. Also, even if the render were to be successful, not resizing the model is going to cause issues with the ground layer being too small: http://imgur.com/ogk3qlM.png

@Scrubs, so I attempted to lock the camera to field of view as you suggested. The option that I found to do that in the View menu below the viewport was greyed out and un-clickable, even though the Camera was selected as the active camera. Is this the correct tick box I should be looking for, or something else?

http://imgur.com/xzIBAb6.png

As always, thanks again for the help!

Regarding your first post, you did not render with your GPU. Blender 2.78 is a bit misleading. In the device option "GPU Compute" is grayed out on your screenshot. To activate GPU rendering, you still need to go to File > User preferences… > System and activate OpenCL or CUDA depending on your graphic card. Your render has been computed using your GPU.

When you do so, you will see that "GPU Compute" is not grayed out anymore. The option "Open Shading Language" also disappeares. The round edge shader is using OSL which GPU ignores. This is the way it is and I cannot do anything for this. If you want the round edges you have to render on CPU. No other options for Blender Cycles.

To attach the camera to the viewport controls:

Scrubs, thank you so much for the help! Switching the default to CUDA in preferences, and then running it with GPU worked perfectly. Can't thank you guys enough for being patient with my technological ineptitude and helping work through the issue with us!

@Legosim
Just remember that rendering on GPU with the basic template you will lose the round edge shader (shiny edges) and some realism because of that (my earlier renderings miss them too 😕)!

Hi, I have been looking for for the Blender Template as you are telling in the video and I coudn't find it. Where can I find it? I liked to render my model of the bridge. Thanks very much.

It's in the Shop section. You've to add it to your cart to be able to download it (don't worry, it's free). You can then download it under Purchases after clicking your user name in the upper right.

Thanks very much, I am going to do that.

@Lilli83
"I liked to render my model of the bridge."
😮 Okay, very ambitious first render, how many parts are actually in the scene? It may take a long time and some memory to render this thing...

Remember, if you use Blender 2.78, do not scale down the model like in the video. Instead move the camera away. There is a bug in the round edge shader and this version of Blender.

Is that bug the artifacts appearing on transparent objects or that dotted line issue I've seen?

No no it is just not scaling down the round edges and therefore they are way too big.

Is it fixable by manually scaling the round edge shader down to the right level? Or would that be difficult to calculate?

No. Node input values are correct. I believe, they may be something wrong in the shader code or somewhere else.
Anyway, It is actually more correct to work without scaling (like in the advanced script). Units are set to mm and are accurate to the real world.

@NCGHunter2
You were right, I tried to render it yesterday but it needed to much time 😦
Will try something else.
Thanks to Scrubs, the video was really helpfull, well done.

I believe I've followed every step correctly, but when I hit "Run Script" it tells me "Report: Error Python script fail, look in the console for now..."

I'm not sure what steps to take next to fix this. Does anybody know? Thanks.