Error Message when i close QTDragonHD

Hi, 
i have some problems when i close QTDragonHD. Here is the error message from the report. 

Debug file information:
Note: Using POSIX realtime
[QTvcp.QTVCP.LIB.QT_PDF.PDFVIEWER][[33mWARNING[0m]  PDFViwer - Is python3-poppler-qt5 installed? (PDFViewer.py:15)
[QTvcp.QTVCP.LIB.QT_NGCGUI.NGCGUI][[34mDEBUG[0m]  UI Filename: /usr/lib/python3/dist-packages/qtvcp/lib/qt_ngcgui/ngcgui.ui (ngcgui.py:458)
[QTvcp.QTVCP.LIB.QT_NGCGUI.NGCGUI][[34mDEBUG[0m]  UI Filename: /usr/lib/python3/dist-packages/qtvcp/lib/qt_ngcgui/ngcgui.ui Didn't find a path NGCGUI files (ngcgui.py:485)
/bin/sh: 1: gnome-session-quit: not found
/usr/bin/linuxcnc: Zeile 963: 93632 Speicherzugriffsfehler  $EMCDISPLAY -ini "$INIFILE" $EMCDISPLAYARGS $EXTRA_ARGS
93594
93629
Stopping realtime threads
Unloading hal components
Note: Using POSIX realtime

I hope you can help me 

regards

This is an on going problem for Qtvcp that we haven't tracked down.
It looks scary but is actually just an annoyance.