Hello,

when I try to install kdenlive I'm getting error massage

E: /var/cache/apt/archives/librttr-core0.9.6_0.9.6+dfsg1-2_amd64.deb: trying to overwrite '/usr/lib/x86_64-linux-gnu/librttr_core.so.0.9.6', which is also in package librttr0 0.9.6-0~ubuntu19.10.1

It happened just after upgrading from kubuntu 19.04 to 19.10.

how can I fix it?

Sorry, my early RTTR package did not exactly follow Debian/Ubuntu naming conventions, so it interferes with the official package.
You should remove librttr0 package before re-installing kdenlive.
It seems it could be automated by writing a transition package, but I didn't have time to read & test the explanations.
Good luck

Thank you,

I marked librttr0 for complete removal via "synaptic package manager" and then reinstalled kdenlive.