When I render my video, it always adds about fifteen seconds of space to the end. When I play it from the timeline, it stopped at the proper place. I tried clicking on remove space to the right on the timeline, but it has no effect. Any ideas?

I actually had this seen just a week ago, if my memory serves me right. I placed a clip beyond the last clip in the timeline, then I immediately deleted it again from the timeline. This cleared the situation and rendering properly stopped at the end.

Thank you very much for the suggestion, but it didn't do the trick for me. Not only that, but the added space grows longer with the length of the rendered video. It is now adding more than three minutes to the finished product. Does anyone else have an idea? Thanks!!!!

Just having the relation between estimated length and actual length in mind: Which framerate have the clips, which framerate are you rendering to? Could be a miscalculation somewhere in the program code...

And as a workaround: You can use ffmpeg to trim the output clip without re-rendering:
ffmpeg -i render.mp4 -ss 00:00:00 -to <expected length hh:mm:ss> -c copy corrected.mp4

Hello,
For your render, do you try to set a timeline zone instead of rendering full project ?

I forgot about ffmpeg. That would certainly do the trick. Thank you for reminding me. However, I would still be interested in why it is doing this, if anyone has an idea. It would be nice to save a step. Thanks again!!!

Then please file a bug report and attach a minimized Kdenlive project that still triggers the bug. Minimizing the project can be tricky but is important.