Explorer.exe - application error

Sorry, my first report, so a lot of things maybe reported wrong:

I run Virtual Box 5.1.8 with livecd-73147-dbg.iso. 2016-11-05-r73147.

1)
Sometimes the CD hangs at HIDUSB.SYS when booting. Not reproducable.

2)
When starting "LiveCD-debug" with US keyboard layout and moving up the start button I get an explorer.exe - application error message: The instruction at "0x7b23b95a" reference memory at "0x0......1". The memory could not be read. OK / Cancel. This message always appears if I move the mouse between "Settings - Documents - Programs". If I move the mouse outside of the "Documents" field from Settings to Programs nothing happens. If I move downwards to Documents the application error appears again. Independent if you click on OK or on Cancel the whole START menu disappears then, so that no standard shutdown or another menu choice is possible. This was reproducable several times.
The desktop symbols also disappear so that there is only an empty desktop.