When I try to play a video in Kdenlive it closes without any reason. There was not any notification about this, I took the log and there's this messages:

Jul 10 19:09:06 Rafael-desktop gnome-session[1605]: QXcbConnection: XCB error: 8 (BadMatch), sequence: 7899, resource id: 60817680, major code: 130 (Unknown), minor code: 3
Jul 10 19:09:06 Rafael-desktop gnome-session[1605]: QXcbConnection: XCB error: 8 (BadMatch), sequence: 7947, resource id: 60817680, major code: 130 (Unknown), minor code: 3
Jul 10 19:09:10 Rafael-desktop gnome-session[1605]: QXcbConnection: XCB error: 8 (BadMatch), sequence: 19520, resource id: 60817680, major code: 130 (Unknown), minor code: 3
Jul 10 19:09:10 Rafael-desktop gnome-session[1605]: QXcbConnection: XCB error: 8 (BadMatch), sequence: 19548, resource id: 60817680, major code: 130 (Unknown), minor code: 3
Jul 10 19:09:10 Rafael-desktop gnome-session[1605]: QXcbConnection: XCB error: 8 (BadMatch), sequence: 19639, resource id: 60817680, major code: 130 (Unknown), minor code: 3
Jul 10 19:09:11 Rafael-desktop gnome-session[1605]: nouveau: kernel rejected pushbuf: Arquivo ou diretório não encontrado
Jul 10 19:09:11 Rafael-desktop gnome-session[1605]: nouveau: ch0: krec 0 pushes 0 bufs 2 relocs 0
Jul 10 19:09:11 Rafael-desktop gnome-session[1605]: nouveau: ch0: buf 00000000 00000002 00000004 00000004 00000000
Jul 10 19:09:11 Rafael-desktop gnome-session[1605]: nouveau: ch0: buf 00000001 00000006 00000004 00000000 00000004
Jul 10 19:09:11 Rafael-desktop kernel: [ 8475.196277] nouveau E[kdenlive[5804]] Unknown handle 0x0000001d
Jul 10 19:09:11 Rafael-desktop kernel: [ 8475.196286] nouveau E[kdenlive[5804]] validate_init
Jul 10 19:09:11 Rafael-desktop kernel: [ 8475.196287] nouveau E[kdenlive[5804]] validate: -2
Jul 10 19:09:12 Rafael-desktop kernel: [ 8476.033404] show_signal_msg: 45 callbacks suppressed
Jul 10 19:09:12 Rafael-desktop kernel: [ 8476.033411] FrameRenderer[5821]: segfault at 8 ip 00007f967805f58c sp 00007f96477fd680 error 4 in libdrm_nouveau.so.2.0.0[7f967805c000+6000]

I don't know what's the true problem, and I took a picture of the drivers of the system to show if necessary cause I saw a mistake on driver in the log. The picture of the avaliable drivers. https://imgur.com/MWfjG9G

Ubuntu 15.10 Kdenlive 4:15.12.1

And english isn't my native language, and what I wrote maybe may not be all right. My native language is portuguese.

Try disabling GPU processing or use Nvidia drivers to see if it helps. Also if you could update to Ubuntu 16.04 and use latest version of Kdenlive.

GPU processing is disabled, I tried to use NVidia driver but Kdenlive doesn't open, I upgraded Kdenlive to latest version and Ubuntu to 16.04 but the problema continues.

please run this in the terminal

rm .config/kdenliverc

and then try.

Now it's working, I tryed do make a video and was successful, I don't know if all it's right, but what was happened don't appear more.

Thanks for the help, if the problem back I'll return to ask for help.