I ran about 10 more experiments using different options and noticed one interesting thing. I found that I only seem to get the crash if I have the internal audio monitor selected as an audio source. Internal audio (but not the monitor) didn't crash in recordings over 20 minutes (normally it crashes within seconds). As such, this is very well likely a duplicate of: https://bugs.launchpad.net/ubuntu/+source/kazam/+bug/1037538 https://bugs.launchpad.net/ubuntu/+source/kazam/+bug/1011918 (although unlike the first bug there, my interface doesn't just "stop", it crashes and disappears altogether) I also ran Kazam with --debug. It didn't give much more enlightening information, but for the record, output was: DEBUG Kazam - Starting ... DEBUG Main - Setting variables. DEBUG PulseAudio - PA - Starting mainloop. DEBUG PulseAudio - PA - Getting API. DEBUG PulseAudio - PA - Setting context. DEBUG PulseAudio - PA - Set state callback. DEBUG PulseAudio - PA - Connecting to server. DEBUG PulseAudio - PA - Start mainloop. DEBUG PulseAudio - PA - Connected. DEBUG Main - Connecting indicator signals. DEBUG Main - Main Window UI setup. DEBUG Main - Getting Audio sources. DEBUG PulseAudio - PA - get_audio_sources() called. DEBUG PulseAudio - PA - pa_sourcelist_cb() DEBUG PulseAudio - - IDX: 0 DEBUG PulseAudio - - Name: alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor DEBUG PulseAudio - - Desc: Monitor of GF110 High Definition Audio Controller Digital Stereo (HDMI) DEBUG PulseAudio - PA - pa_sourcelist_cb() DEBUG PulseAudio - - IDX: 1 DEBUG PulseAudio - - Name: alsa_input.usb-046d_HD_Webcam_C525_ABD5D0D0-00-C525.analog-mono DEBUG PulseAudio - - Desc: HD Webcam C525 Analog Mono DEBUG PulseAudio - PA - pa_sourcelist_cb() DEBUG PulseAudio - - IDX: 2 DEBUG PulseAudio - - Name: alsa_output.pci-0000_00_14.2.analog-stereo.monitor DEBUG PulseAudio - - Desc: Monitor of Built-in Audio Analog Stereo DEBUG PulseAudio - PA - pa_sourcelist_cb() DEBUG PulseAudio - - IDX: 3 DEBUG PulseAudio - - Name: alsa_input.pci-0000_00_14.2.analog-stereo DEBUG PulseAudio - - Desc: Built-in Audio Analog Stereo DEBUG PulseAudio - PA - pa_sourcelist_cb() -- finished DEBUG Main - Device found: DEBUG Main - - 0 DEBUG Main - - alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor DEBUG Main - - Monitor of GF110 High Definition Audio Controller Digital Stereo (HDMI) DEBUG Main - Device found: DEBUG Main - - 1 DEBUG Main - - alsa_input.usb-046d_HD_Webcam_C525_ABD5D0D0-00-C525.analog-mono DEBUG Main - - HD Webcam C525 Analog Mono DEBUG Main - Device found: DEBUG Main - - 2 DEBUG Main - - alsa_output.pci-0000_00_14.2.analog-stereo.monitor DEBUG Main - - Monitor of Built-in Audio Analog Stereo DEBUG Main - Device found: DEBUG Main - - 3 DEBUG Main - - alsa_input.pci-0000_00_14.2.analog-stereo DEBUG Main - - Built-in Audio Analog Stereo DEBUG Main - Getting Video sources. DEBUG Main - Found 1 monitors. DEBUG Main - Monitor 0 - X: 0, Y: 0, W: 1920, H: 1080 DEBUG Main - Video Toggled. DEBUG Main - Audio1 Toggled. DEBUG Main - Restoring state - sources: V (0), A_1 (0), A_2 (-1) DEBUG Main - Video changed. DEBUG Main - New Video: {'y': 0, 'x': 0, 'height': 1080, 'width': 1920} DEBUG Main - Audio Changed. DEBUG Main - - A_1 0 DEBUG Main - - A_2 -1 DEBUG Main - - PA Audio1 IDX: 0 DEBUG Main - - PA Audio2 IDX: 3 DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 0 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 0 DEBUG PulseAudio - - Name: alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor DEBUG PulseAudio - - Desc: Monitor of GF110 High Definition Audio Controller Digital Stereo (HDMI) DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 3 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 3 DEBUG PulseAudio - - Name: alsa_input.pci-0000_00_14.2.analog-stereo DEBUG PulseAudio - - Desc: Built-in Audio Analog Stereo DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG Main - New Audio1: Monitor of GF110 High Definition Audio Controller Digital Stereo (HDMI) DEBUG Main - New Audio2: Built-in Audio Analog Stereo DEBUG Main - Getting volume info. DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 0 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 0 DEBUG PulseAudio - - Name: alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor DEBUG PulseAudio - - Desc: Monitor of GF110 High Definition Audio Controller Digital Stereo (HDMI) DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 3 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 3 DEBUG PulseAudio - - Name: alsa_input.pci-0000_00_14.2.analog-stereo DEBUG PulseAudio - - Desc: Built-in Audio Analog Stereo DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG Main - Restoring state - volume: A_1 (60.0), A_2 (26.3593832838) DEBUG Main - Volume 1 changed, new value: 60.0 DEBUG Main - Volume 2 changed, new value: 26.3593832838 DEBUG Main - Codec changed. DEBUG Main - Cursor capturing ON. DEBUG Main - Audio Changed. DEBUG Main - - A_1 1 DEBUG Main - - A_2 -1 DEBUG Main - - PA Audio1 IDX: 1 DEBUG Main - - PA Audio2 IDX: 3 DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 1 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 1 DEBUG PulseAudio - - Name: alsa_input.usb-046d_HD_Webcam_C525_ABD5D0D0-00-C525.analog-mono DEBUG PulseAudio - - Desc: HD Webcam C525 Analog Mono DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 3 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 3 DEBUG PulseAudio - - Name: alsa_input.pci-0000_00_14.2.analog-stereo DEBUG PulseAudio - - Desc: Built-in Audio Analog Stereo DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG Main - New Audio1: HD Webcam C525 Analog Mono DEBUG Main - New Audio2: Built-in Audio Analog Stereo DEBUG Main - Audio2 Toggled. DEBUG Main - Audio Changed. DEBUG Main - - A_1 1 DEBUG Main - - A_2 2 DEBUG Main - - PA Audio1 IDX: 1 DEBUG Main - - PA Audio2 IDX: 2 DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 1 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 1 DEBUG PulseAudio - - Name: alsa_input.usb-046d_HD_Webcam_C525_ABD5D0D0-00-C525.analog-mono DEBUG PulseAudio - - Desc: HD Webcam C525 Analog Mono DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - get_source_info_by_index() called. IDX: 2 DEBUG PulseAudio - PA - pa_sourceinfo_cb() DEBUG PulseAudio - - IDX: 2 DEBUG PulseAudio - - Name: alsa_output.pci-0000_00_14.2.analog-stereo.monitor DEBUG PulseAudio - - Desc: Monitor of Built-in Audio Analog Stereo DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- Hit EOL DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- EOL no data! DEBUG PulseAudio - PA - pa_sourceinfo_cb() -- finished DEBUG Main - New Audio1: HD Webcam C525 Analog Mono DEBUG Main - New Audio2: Monitor of Built-in Audio Analog Stereo DEBUG Main - Record clicked, invoking Screencast. /usr/lib/python2.7/dist-packages/gobject/constants.py:24: Warning: g_boxed_type_register_static: assertion `g_type_from_name (name) == 0' failed import gobject._gobject DEBUG GStreamer - Capture Cursor: True DEBUG GStreamer - Framerate : True DEBUG GStreamer - Coordinates: 0 0 1919 1079 DEBUG GStreamer - Codec: H264/MP4 /usr/lib/python2.7/dist-packages/kazam/backend/gstreamer.py:156: Warning: value "7" of type `guint' is invalid or out of range for property `threads' of type `guint' self.videnc.set_property("threads", self.cores) DEBUG GStreamer - Audio1 Source: alsa_input.usb-046d_HD_Webcam_C525_ABD5D0D0-00-C525.analog-mono DEBUG GStreamer - Audio2 Source: alsa_output.pci-0000_00_14.2.analog-stereo.monitor DEBUG GStreamer - Filesink: /tmp/kazam_6Nl3t4.movie DEBUG GStreamer - Pipline - Video + Dual Audio DEBUG Main - Hiding main window. DEBUG Main - Start request. INFO Indicator - Recording started. DEBUG GStreamer - Generating dot file. DEBUG GStreamer - Setting STATE_PLAYING mmap() failed: Cannot allocate memory Assertion 'b' failed at pulsecore/memblock.c:454, function pa_memblock_acquire(). Aborting. Aborted (core dumped)