Snap installed shotcut cannot export

Ubuntu 19.04 ,installed using " snap install shotcut --classic"
Any attempt to export video fail with:

QStandardPaths: XDG_RUNTIME_DIR points to non-existing path ‘/run/user/1000/snap.shotcut’, please create it with 0700 permissions.

[libx264 @ 0x7f9900001e80] using SAR=1/1

[libx264 @ 0x7f9900001e80] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX

[libx264 @ 0x7f9900001e80] profile High, level 4.0, 4:2:0, 8-bit

[libx264 @ 0x7f9900001e80] 264 - core 157 r2945 72db437 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=1 ref=2 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=6 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=120 keyint_min=12 scenecut=40 intra_refresh=0 rc_lookahead=30 rc=crf mbtree=1 crf=21.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00

[h264 @ 0x7f98e414c040] Reinit context to 1920x800, pix_fmt: yuv420p

[h264 @ 0x7f98e41803c0] Reinit context to 1920x800, pix_fmt: yuv420p

[h264 @ 0x7f98e4661300] Reinit context to 1920x800, pix_fmt: yuv420p

[producer avformat] audio: total_streams 1 max_stream 1 total_channels 2 max_channels 2

[AVIOContext @ 0x7f98e414aec0] Statistics: 5012452 bytes read, 0 seeks

[producer avformat-novalidate] /run/user/1000/gvfs/smb-share:server=192.168.1.20,share=(path was here).mp4

checking VFR: pkt.duration 500

[h264 @ 0x7f98e43148c0] Reinit context to 1920x800, pix_fmt: yuv420p

[mp4 @ 0x7f9900000f00] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.

[mp4 @ 0x7f9900000f00] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.

[h264 @ 0x7f9894834e40] Reinit context to 1920x800, pix_fmt: yuv420p

[h264 @ 0x7f9897f1f800] Reinit context to 1920x800, pix_fmt: yuv420p

[h264 @ 0x7f9897f23840] Reinit context to 1920x800, pix_fmt: yuv420p

[producer avformat] audio: total_streams 1 max_stream 1 total_channels 2 max_channels 2

[AVIOContext @ 0x7f988a410dc0] Statistics: 5012452 bytes read, 0 seeks

[producer avformat-novalidate] /run/user/1000/gvfs/smb-share:server=192.168.1.20,share=(path to infile was here).mp4

checking VFR: pkt.duration 500

[h264 @ 0x7f98e4e2b580] Reinit context to 1920x800, pix_fmt: yuv420p

Failed with exit code 11

Failed with exit code 11

/run/user/1000/gvfs/smb-share:server=192.168.1.20,share=(path was here).mp4

Does it work if you do not use a samba share through GNOME? Is this file available to all processes, e.g. at command line?

yes, using local files as source works for the snap,

Last I checked, only GNOME software can work with GNOME virtual file systems/mounts. This is typical on Linux, and many apps are not GNOME including Shotcut and cannot work with files on those mounts.