It has appeared recently, and one happens in spot (in ~50% of cases).Restart of the kdenlive doesn't help.Sometimes a swapping of clips in tracks fixes it.Sometimes just a razoring of first clip (shortly before transition) fixes it.Sometimes it's unwinnable.
Registered users: bancha, Bing [Bot], daret, Evergrowing, Google [Bot], lockheed, sandyvee, Sogou [Bot]