So I have put together a video for my business's YT channel. In the project, I have a .kdenlive file as an intro, a couple short music clips, and 2 video clips. Effects are nothing crazy - some pan/zoom, some fade in/out, and I have one of the title clips composited over the whole thing as a watermark. When I render, the output file is black and says "INVALID" in large white letters.

I have played with this for several hours over the last few nights, and have narrowed it down a bit. If I remove just the composited watermark title clip, it will almost work. I can render a selection and it works perfectly. If I render the whole project, the output shows "INVALID" on top of the functioning video! Strange. So why would parts render properly, but not the whole thing? Removing other files and clips don't make any difference.

Are there any log files that would offer some insight to this rediculously frustrating issue that shouldn't be?

I am using Kdenlive 0.9.2 on Ubuntu 12.04. Trying to render at 720 30fps 12000 128K mp4. Clip is about 4 minutes 30 seconds. Takes around 28 minutes for a 2 pass render.

are you sure you have all the codecs installed to render to h264? what audio are you choosing to render to? i am using xubuntu 12.04 and sunab's kdenlive-release ppa along with medibuntu for the libav* extras and ffmpeg. not sure of any log files anywhere.

Almost sounds like someone playing a joke on you.

How about rendering to mpeg2 or dv video to see if it shows up?

I would also do a total purge uninstall then reinstall from a known good source, to start fresh, just in case some config file is doing this.
ffmpeg also purge and reinstall.