I want to create a motion tracking with Auto Mask. The first attempt didn't looked good so I started another one. Now I'm receiving this message:

Clip already contains analysis data Motion vectors - join / add ? (sorry, German GUI)

Whichever option I chose, Kdenlive crashes.

How can I remove the motion tracking data from the clip properties?

And where can I check the analysis progress?

Have a look at the youtube video at http://userbase.kde.org/Kdenlive/Manual/Effects/Blur_and_hide/Auto_Mask - it shows where you can check analysis progress.

You can delete the motion tracking data from the clip properties dialog on the metadata tab.

Tanks! :)

Unfortunately there is a reproducible error: if I delete the Motion vectors of the clip, save the project and ad new ones (via Auto Mask), Kdenlive crashes. It only works properly for me if I start a new Project (even with the same clips).

And also I can't ad a Motion tracking where the e.g. title starts outside the frame. I added a title clip with Affine-Effect and x=-1000 in the first keyframe but after importing the keyframes from the clip, the title clip starts in the middle of the frame not at -1000. :( The only way it may work seems to modify all keyframes by hand.

I suggest you submit bugs at mantis about the crash.

I find that I can not reproduce your issue though.

Are you following instructions at http://userbase.kde.org/Kdenlive/Manual/Effects/Blur_and_hide/Auto_Mask#Motion_Tracking

As to the issue to make the title clip start off the frame. I also find what you find. But this is exactly as you would expect it to behave. You have edited the first key frame to mark it start off the screen. And then the very next keyframe (1/24th of a second later) you title is at the in the middle of the clip because that is where you have told it to go.

So it sounds like you want to use half auto-generated motion tracking and half manual. This means you need to do manual work.
You could use the "reset frames before cursor" to get rid of all the motion tracking that you don't want and then add a handful of manual key frames to define where you want it to go in the beginning. Kdenlive interpolates the motion between keyframes for you - so you don't need a key frame at every frame like you get with the automask effect.