I have a very simple movie to be done.
One track is a slide show - no problem, used slide show clip
Second clip should be a kind of sub-titel. So I made a dark beam in the bottom, Alfa 175 means a little bit transparent, and put a text in top of it.

Now, I can see in clip monitor aas well as in the render version the Text, but not the beam. The beam is disapeared.

HCP,

which Kdenlive version are you using? Up to 15.08.x, Kdenlive tracks don't work like layers out of the box: that means, that at any given time, only the frame ("image") of one track wins. You'll need to use transitions in order to compose the result frame/image from the images coming from multiple tracks simultaneously. And you will need to learn a little bit about transitions and how they work in Kdenlive's timeline. The timeline isn't exactly intuitive, no pun intended.

While tracks in Kdenlive (and MLT that is beneith Kdenlive) are not layers, the way transitions work in Kdenlive's timeline, you often need the things that are going "on top" of the final image on a track higher up in the timeline. There are minor exceptions to this rule, but this need deeper understanding of the composition tree you can set up using multiple transitions and tracks. Forget about this now.

Say you have your tracks T1 and T2. Please throw your slideshow clip onto T2, the lower one.

Now put your titling clip onto T1, that is, the track above the slideslow clip track. Next, add a transition to the titling clip on T1, such as a composite transition. This transition will now tell Kdenlive to combine your title clip with the slideshow clip on the track below. Only now any alpha information in the clip on T1 becomes "alive". For the moment, use adjacent tracks. Transitions can also combine non-adjacent tracks, but that's for later when you gained some confidence in working with Kdenlive.

Without the transition on the clip on T1, Kdenlive will look for a clip on the topmost track and only render that. It will ignore any alpha information that may be present. The important gotcha here is that only transitions will use alpha information when somehow mangling clips on separate tracks into a single output image/frame.

I would like to suggest reading about Kdenlive's transition model (touting my own horn):

• Kdenlive Timeline Illustrated, Part 1
• Kdenlive Timeline Illustrated, Part 2

Thanks for fast answer. My kids "pulled" me out to fitness why I had this break in work here

I have actually Opensuse 13.2 - 4.14.9 with Kdenlive 0.9.10. This version crashes from time to time. I think there are some updates?
I like Kdenlive - used Pinnacle over maybe 15 years before. I have cut lot of movies before, some with Kdenlive. Kdenlive has a lot of option - if we can find them. It's nicely made. But sometimes it is irritating.

I did as mentioned: Pulled the title clip on video1 and the clips (pictures) on video3 - will not go to video2.
Same result.
But the problem is like that:
I have made a title clip. In the title clip I put a rectangle in the bottom as a beam; black, half transparent. In top of these beam I placed a text. In the tile clip everything is fine. The rectangle is made because I can't colour a text box background and need a colour stable background for text.
When I place the title clip in video 1 or 2 , with transition, in the time line, all is fine. I can see a overlay of text on video. But, I can't see my black half transparent beam any more. this beam is disappeared.
Means: I have a clip containing a square and text and a movie clip. but the square is gone in combination.

Now I tested....
I opened the tilte clip, add a red square and a picture into the clip. Now we can the red square, text and picture in top of video.
the I put the red block behind the text - works.
I make the red block black - works (means I can see block, text and video.

Ahhh: When I add "effect blur" to the block, it disappears. And I need not to chose "addition" but "composite". Otherwise the block disappears.

thanks for help. This muse be a bug in software we found here....?

The "addition" transitions does something completely different from what you may seem to expect. You'll need either the "affine" or "composite" transitions. The key difference is that...

• affine allows for rotation, scaling, and opacity, but no swiping.
• composite does opacity, optionally controlled by swiping using luma images, but can't do rotation and scaling.

So, now what does the addition transition do? It simply adds up for each pixel in the images from both tracks their individual channel values R, G, B, and alpha. So the outcome in your cast won't be what you want to achieve. Addition can be used to compose light images on top of dark images. However, most of the time the outcome will be terrible, and lighten is another transition to be used when composing lighter areas on top of darker regions.