instantiating QML MediaStore component crashes if index can't be opened

App crashes during start.
This app just works for me 1 time each 6 times proximately in all versions that I used from ubuntu (bq 4.5 ubuntu edition)

This is one of the logs from one crash:

ThumbnailerImageResponse::dbusCallFinished(): D-Bus error: "Request cancelled"
libust[15292/15337]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15292/15336]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
UbuntuWindow::handleSurfaceFocusChange(focused=false)
** Application is now inactive
libust[15457/15460]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15460]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15461]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15461]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
Loading module: 'libubuntu_application_api_touch_mirclient.so.3.0.0'
/usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene: unrecognized option '--url='
/usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene: invalid option -- 'I'

(process:15457): dconf-WARNING **: Unable to open /custom/xdg/data/dconf/profile/custom: Permission denied

(process:15457): dconf-WARNING **: unable to open named profile (custom): using the null configuration.
libust[15457/15483]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15483]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15484]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15484]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
terminate called after throwing an instance of 'std::runtime_error'
  what(): Tried to open a db with schema version -1, while supported version is 9.

In this file there was also advices saying that numerous thumbnailer request was failed but I think that it is normal...
If you need the complete log just tell me.

I talk with some people that told me that the app works fine form them so i think that maybe the app is trying to open some corrupted files or files that it can't manage.
Additional info: I'm using as /home/phablet/Music folder a symbolic link for my SD card Music folder.