digiKam 5.4.0 crashes on Rebuilding Thumbnails

[Andrey Goreev]

digiKam crashes on me whenever I try to rebuild thumbnails.
Here is what the terminal says:
"
digikam.general: stage1
digikam.general: stage2
digikam.general: Using  4  CPU core to run threads
digikam.general: Using  1  CPU core to run threads
QXcbConnection: XCB error: 3 (BadWindow), sequence: 3317, resource id: 
44040800, major code: 40 (TranslateCoords), minor code: 0

(process:11458): GLib-ERROR **: Creating pipes for GWakeup: Too many open files

Trace/breakpoint trap
"

Any solution for that?
Linux Mint 18.1 KDE
sqlite