Hi...
That's my problem, I Can't render project if title clips ar present. If I take them out I can render to all kind of files.
I don't know if you need more info, probably, please ask me for it.
I use arch linux.
best regards and thanks

this is a known issue.

This is a recommended workaround as described http://www.kdenlive.org/mantis/view.php?id=2592

"The problem is related to 2 frei0r effects using OpenCV. I have not yet found a fix, but as a workaround, you can delete (or move to a backup location) the files:

/usr/lib/frei0r-1/facebl0r.so /usr/lib/frei0r-1/facedetect.so

After that, rendering should work fine. Still working on a real fix."

Interesting...
Discovered I cannot render in root mode but can in user login. Root cant see the mlt6 stuff. Odd ...
I can develop in root but need to change to non-root to make a H264 which went well and is on Youtube.
Thanx KDENLIVE team...Marc