SUMMARY
If you click on a timeline of Kdenlive, the apli will crash.
Every PC is same problem.

STEPS TO REPRODUCE
1. Click timeline.

OBSERVED RESULT
kdenlive
kdenlive: /usr/lib/libmlt.so.6: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
kdenlive: /usr/lib/libmlt++.so.3: no version information available (required by kdenlive)
mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltrtaudio.so
  (librtaudio.so.6: 共有オブジェクトファイルを開けません: そのようなファイルやディレクトリはありません)
mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltgdk.so
  (/usr/lib/mlt/libmltgdk.so: undefined symbol: pango_ft2_font_map_create_context)
mlt_repository_init: failed to dlopen /usr/lib/mlt/libmltsox.so
  (libsox.so.3: 共有オブジェクトファイルを開けません: そのようなファイルやディレクトリはありません)
KTranscript: Loaded module: /usr/share/locale/ja/LC_SCRIPTS/ki18n5/ki18n5.js
"resample" is blacklisted
WARNING : Fails to parse  "avcolour_space"
WARNING : Fails to parse  "avcolor_space"
WARNING : Fails to parse  "avdeinterlace"
WARNING : Fails to parse  "swscale"
"avfilter.abench" is blacklisted
"avfilter.acompressor" is blacklisted
"avfilter.adelay" is blacklisted
"avfilter.aecho" is blacklisted
"avfilter.aemphasis" is blacklisted
"avfilter.aeval" is blacklisted
"avfilter.afade" is blacklisted
"avfilter.afftfilt" is blacklisted
"avfilter.agate" is blacklisted
"avfilter.ametadata" is blacklisted
"avfilter.arealtime" is blacklisted
"avfilter.ashowinfo" is blacklisted
"avfilter.channelmap" is blacklisted
"avfilter.chorus" is blacklisted
"avfilter.earwax" is blacklisted
"avfilter.volume" is blacklisted
"avfilter.volumedetect" is blacklisted
"avfilter.ass" is blacklisted
"avfilter.atadenoise" is blacklisted
"avfilter.avgblur" is blacklisted
"avfilter.bbox" is blacklisted
"avfilter.bench" is blacklisted
"avfilter.blackdetect" is blacklisted
"avfilter.blackframe" is blacklisted
"avfilter.boxblur" is blacklisted
"avfilter.bwdif" is blacklisted
"avfilter.chromakey" is blacklisted
"avfilter.colorkey" is blacklisted
"avfilter.colormatrix" is blacklisted
"avfilter.colorspace" is blacklisted
"avfilter.convolution" is blacklisted
"avfilter.crop" is blacklisted
"avfilter.cropdetect" is blacklisted
"avfilter.curves" is blacklisted
"avfilter.datascope" is blacklisted
"avfilter.dctdnoiz" is blacklisted
"avfilter.deband" is blacklisted
"avfilter.deflate" is blacklisted
"avfilter.deinterlace_vaapi" is blacklisted
"avfilter.deshake" is blacklisted
"avfilter.despill" is blacklisted
"avfilter.doubleweave" is blacklisted
"avfilter.drawbox" is blacklisted
"avfilter.drawgraph" is blacklisted
"avfilter.drawgrid" is blacklisted
"avfilter.drawtext" is blacklisted
"avfilter.elbg" is blacklisted
"avfilter.eq" is blacklisted
"avfilter.fade" is blacklisted
"avfilter.field" is blacklisted
"avfilter.fieldhint" is blacklisted
"avfilter.fieldorder" is blacklisted
"avfilter.find_rect" is blacklisted
"avfilter.floodfill" is blacklisted
"avfilter.fspp" is blacklisted
"avfilter.gblur" is blacklisted
"avfilter.geq" is blacklisted
"avfilter.hflip" is blacklisted
"avfilter.hqdn3d" is blacklisted
"avfilter.hqx" is blacklisted
"avfilter.hue" is blacklisted
"avfilter.hwdownload" is blacklisted
"avfilter.idet" is blacklisted
"avfilter.il" is blacklisted
"avfilter.lenscorrection" is blacklisted
"avfilter.loop" is blacklisted
"avfilter.lumakey" is blacklisted
"avfilter.lut" is blacklisted
"avfilter.lutrgb" is blacklisted
"avfilter.lutyuv" is blacklisted
"avfilter.mcdeint" is blacklisted
"avfilter.metadata" is blacklisted
"avfilter.negate" is blacklisted
"avfilter.nlmeans" is blacklisted
"avfilter.nnedi" is blacklisted
"avfilter.owdenoise" is blacklisted
"avfilter.pad" is blacklisted
"avfilter.perspective" is blacklisted
"avfilter.phase" is blacklisted
"avfilter.pixscope" is blacklisted
"avfilter.pp" is blacklisted
"avfilter.pp7" is blacklisted
"avfilter.prewitt" is blacklisted
"avfilter.realtime" is blacklisted
"avfilter.removegrain" is blacklisted
"avfilter.removelogo" is blacklisted
"avfilter.roberts" is blacklisted
"avfilter.rotate" is blacklisted
"avfilter.scale_vaapi" is blacklisted
"avfilter.showinfo" is blacklisted
"avfilter.shuffleframes" is blacklisted
"avfilter.sidedata" is blacklisted
"avfilter.signalstats" is blacklisted
"avfilter.sobel" is blacklisted
"avfilter.stereo3d" is blacklisted
"avfilter.super2xsai" is blacklisted
"avfilter.swapuv" is blacklisted
"avfilter.tblend" is blacklisted
"avfilter.tlut2" is blacklisted
"avfilter.tonemap" is blacklisted
"avfilter.transpose" is blacklisted
"avfilter.vectorscope" is blacklisted
"avfilter.vflip" is blacklisted
"avfilter.vignette" is blacklisted
"avfilter.vmafmotion" is blacklisted
"avfilter.w3fdif" is blacklisted
"avfilter.xbr" is blacklisted
"avfilter.yadif" is blacklisted
"avfilter.zoompan" is blacklisted
WARNING : Fails to parse  "swresample"
WARNING : Fails to parse  "deinterlace"
WARNING : Fails to parse  "jack"
"jackrack" is blacklisted
WARNING : Fails to parse  "glsl.manager"
WARNING : Fails to parse  "movit.convert"
WARNING : Fails to parse  "movit.crop"
WARNING : Fails to parse  "movit.resample"
WARNING : Fails to parse  "movit.resize"
"frei0r.3dflippo" is blacklisted
"frei0r.bluescreen0r" is blacklisted
"frei0r.bw0r" is blacklisted
"frei0r.gamma" is blacklisted
"frei0r.invert0r" is blacklisted
"frei0r.rgbsplit0r" is blacklisted
"frei0r.tehRoxx0r" is blacklisted
"frei0r.transparency" is blacklisted
"frei0r.vertigo" is blacklisted
"motion_est" is blacklisted
WARNING : Fails to parse  "crop_detect"
WARNING : Fails to parse  "BurningTV"
"burningtv" is blacklisted
WARNING : Fails to parse  "lumaliftgaingamma"
WARNING : Fails to parse  "rotoscoping"
WARNING : Fails to parse  "telecide"
WARNING : Fails to parse  "audiochannels"
WARNING : Fails to parse  "audioconvert"
WARNING : Fails to parse  "data_feed"
"data_show" is blacklisted
WARNING : Fails to parse  "imageconvert"
"mask_apply" is blacklisted
"mask_start" is blacklisted
"mono" is blacklisted
"region" is blacklisted
"resize" is blacklisted
"transition" is blacklisted
"watermark" is blacklisted
"qtext" is blacklisted
"rgblut" is blacklisted
"spot_remover" is blacklisted
"text" is blacklisted
"timer" is blacklisted
WARNING : Fails to parse  "deshake"
WARNING : Fails to parse  "vidstab"
++++++ Unknown asset :  "avfilter.acompressor"
++++++ Unknown asset :  "avfilter.aecho"
++++++ Unknown asset :  "avfilter.agate"
Warning: duplicate custom definition of effect "frei0r.alpha0ps" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_alpha0ps.xml"
Warning: duplicate custom definition of effect "frei0r.balanc0r" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_balanc0r.xml"
Warning: duplicate custom definition of effect "frei0r.curves" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_curves.xml"
++++++ Unknown asset :  "frei0r.facebl0r"
++++++ Unknown asset :  "frei0r.facedetect"
Warning: duplicate custom definition of effect "frei0r.levels" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_levels.xml"
Warning: duplicate custom definition of effect "frei0r.lightgraffiti" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_lightgraffiti.xml"
Warning: duplicate custom definition of effect "frei0r.select0r" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_select0r.xml"
Warning: duplicate custom definition of effect "frei0r.sopsat" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/frei0r_sopsat.xml"
++++++ Unknown asset :  "frei0r.tehRoxx0r"
++++++ Unknown asset :  "frei0r.vertigo"
++++++ Unknown asset :  "frei0r.vertigo"
++++++ Unknown asset :  "movit.unsharp_mask"
Warning: duplicate custom definition of effect "qtblend" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/qtblend.xml"
++++++ Unknown asset :  "region"
++++++ Unknown asset :  "rotoscoping"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "sox"
++++++ Unknown asset :  "timewarp"
Warning: duplicate custom definition of effect "opencv.tracker" found. Only last one will be considered. Duplicate found in "/usr/share/kdenlive/effects/tracker.xml"
++++++ Unknown asset :  "vidstab"
"frei0r.alphainjection" is blacklisted
"frei0r.blend" is blacklisted
"frei0r.composition" is blacklisted
"frei0r.xfade0r" is blacklisted
Cyclic dependency detected between "file:///usr/lib/qt/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml" and "file:///usr/lib/qt/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml"
Cyclic dependency detected between "file:///usr/lib/qt/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml" and "file:///usr/lib/qt/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
Cyclic dependency detected between "file:///usr/lib/qt/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml" and "file:///usr/lib/qt/qml/org/kde/kirigami.2/styles/org.kde.desktop.plasma/Units.qml"
QQmlEngine::setContextForObject(): Object already has a QQmlContext
qrc:/qml/timeline.qml:1430:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
Loading bin playlist...
//////////////////////
Trying to construct 5 tracks.
////////////////////////////////
SUSPICIOUS: we weren't expecting a producer when parsing the timeline
=== REQUESTING TRACK INSERTION AT:  -1
=== REQUESTING TRACK INSERTION AT:  -1
=== REQUESTING TRACK INSERTION AT:  -1
=== REQUESTING TRACK INSERTION AT:  -1
WARNING, NO AUDIO BACKEND FOUND
qml: GOT SCALE:  0.66 , BASE:  10  - SNAPPING:  15
WARNING, NO AUDIO BACKEND FOUND
WARNING, NO AUDIO BACKEND FOUND
[1]    66904 segmentation fault (core dumped)  kdenlive

EXPECTED RESULT
Ability of edit.

SOFTWARE/OS VERSIONS
Windows: unclear
macOS: unclear
Linux/KDE Plasma: Manjaro Linux
(available in About System)
KDE Plasma Version: 5.19.4
KDE Frameworks Version: 5.72.0
Qt Version: 5.15.0

ADDITIONAL INFORMATION
Please cure.