crashed when exporting to gif

I halved the frames, turned up the delay to 8 and exported to a gif, but the app crashed with this in terminal:
  WARNING: library configuration mismatch
  avcodec     configuration: --prefix=/usr --extra-version=1build2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared --enable-version3 --disable-doc --disable-programs --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc --enable-netcdf
  libavutil      55. 34.101 / 55. 34.101
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.101 / 57. 56.101
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libavresample   3.  1.  0 /  3.  1.  0
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Reading /tmp/gifine_kihnhhchwg/000000057.png
Reading /tmp/gifine_kihnhhchwg/000000061.png
Reading /tmp/gifine_kihnhhchwg/000000065.png
Reading /tmp/gifine_kihnhhchwg/000000069.png
Reading /tmp/gifine_kihnhhchwg/000000073.png
Input #0, image2pipe, from 'pipe:':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: png, rgb24(pc), 1503x740, 30 fps, 30 tbr, 30 tbn, 30 tbc
[NULL @ 0x55929846fd60] Unable to find a suitable output format for '/home/liam/lol4'
/home/liam/lol4: Invalid argument
PANIC: unprotected error in call to Lua API (/usr/local/share/lua/5.1/gifine/commands.lua:234: bad argument #2 to 'new_from_bytes' (-1 is out of <0, 1.844674407371e+19>))
leafo / gifine

crashed when exporting to gif #15
