Not the issue, wasn't using it anyway as CPU and GPU are rendering in similar speeds.

So instead I actually enabled it and it had no effect, as didn't disabling it again either.

This crash is limited to Sony AVC Codec

What is your source material?

Have you tried rendering to XDCAM-EX.mp4, or .mxf, and uploading that to YouTube?

If you disable all the effects from your clips, do you get a crash?

If you solo a track and attempt a render. do you get a crash?

What is your source footage (camera, format, p or i, etc...)
Does it always crash in exactly the same spot?
Have you tried reinstalling it?

OP, have you seen the Vimeo/youtube tutorial vidmusic has put together? You might change your mind about your process.

Since you say it has started to crash, it implies that it worked before with Sony AVC renders, correct? If so, what's different about this project? Any FX? What happens if you start a new project and just a short video on the timeline and no FX, does it render without crashing?

Thank you for the responses and my excuse I haven't reported back yet. Busy life ;) I will answer all the given questions as detailed as possible.

From "Astar"

"What is your source material?"

Recorded footage with NVIDIA Shadowplay. The output of shadowplay is X264 in MP4 format with 50 mbps for video and audio 196 kbps with 44Khz 2 channel stereo (probably, details lack here)

"Have you tried rendering to XDCAM-EX.mp4, or .mxf, and uploading that to YouTube?"

I have not, though I did notice that the problems sticks to Sony AVC only.

"If you disable all the effects from your clips, do you get a crash?"

I have tried this with purely the source material given or even a standard not edited WMV file and a other MP4 file which still causes the crash.

"If you solo a track and attempt a render. do you get a crash?"
Yes, this didn't change the crash situation.

From "Markk655"

"What is your source footage (camera, format, p or i, etc...)"

See answer above, NVIDIA Shadowplay

"Does it always crash in exactly the same spot?"
Instantly as soon as rendering starts.

Have you tried reinstalling it?

Yes, i have completely removed the software even, thus far that even all codecs that come with the software had to be reinstalled. This did not affect the program and the crashing still exists (which stunned me the most btw)

From "MSmart"

"OP, have you seen the Vimeo/youtube tutorial vidmusic has put together? You might change your mind about your process."

I'm not really following you here. What kind of tutorial and what process to be exact?

"Since you say it has started to crash, it implies that it worked before with Sony AVC renders, correct? If so, what's different about this project? Any FX? What happens if you start a new project and just a short video on the timeline and no FX, does it render without crashing?"

Did the software work before well? Yes this issue started 1 day before posting here. Before that I have worked for over 2 years with pleasure with this method of editing and source files. This is the first time I encounter such and issue of such an error that I have to resort to the forums. As old issues usually had quickly a patch or work around. (I have a work around for now btw)

Any FX? Normally yes, but as common sense also told me, I tried without. This did not change anything.

What is different on this project? Nothing really. No new things are being used no new plugins etc. Nothing new.

new project? As I mentioned completely above I have tried to even render a small bit of pre-rendered footage and footage from different source. This still ended up on an instant crash as soon as rendering starts.

Summary:

The crash is hard to explain. It happens with Sony AVC only and the source doesn't matter nor do any FX matter. What really made me scratch my head was the fact that fully removing the software did not help as it usually should. Which makes me worry wether the OS might be 'infected' (read damaged) for this codec. Despite that for now I work with a different codec knowingly MainConcept AVC/AAC. It appears to be quite similar.

To add for the choice of codec. I've been working for a long time with this as this one used to be 2 years ago the best way. Since then I never really bothered looking into different options. The video's I produce contain high speed gameplay from First Person Shooters and sometimes games with just a load of stuff going on, on screen. As YouTube made things a bit harder as they narrowed their compatibility down I always felt that this was the best solution. So if anyone knows something better I am up for it anyway ;) Footage is always in 1080P 60FPS. I have partnership so bigger bitrates do apply for me on YT.

I think I have pretty much said it all. As for now I really start to think that the error might even be in Windows now. Maybe a file that went corrupt in Vegas and managed to corrupt files in Windows. I dunno we'll see I guess.

Reads like you've tried most things and - odd that no-one else has similar ( although my own recent problem Rendering in .mp4 may yet be my own fault -I'm using also SMSsuite v12 - but 32-bit.).

Have you tried Rendering a piece of Media Generated stuff - i.e. TEXT only ? This is hardly likely to be your fault, since the software created it.
A while ago I had issues with DVDAS - but that appeared to be a Build-issue ( like a fool I updated! ).
Another "test" might be to re-Render an earlier .vf movie which you have completed successfully . . . although that's no help for yr current project and no doub Time is now pressing. If it doesn't crash that's progress ( however, I suspect it will ).

Lastly, hope U don't mind.... What has changed recently? Other Software up-dates, hardware/drivers . . . . Computers can be darn fussy.
Good luck - let us know what's The Fix.