I can confirm this.
But for me knotify4 do not crash every time KDE starts but most of the times. When it crashes it seems to kill the kdm process so I'll return to the login screen.
[...]
Oct 20 19:09:21 frodo kdm_greet[8912]: Cannot open default user face
Oct 20 19:09:30 frodo kernel: [ 992.814251] knotify4[9148]: segfault at 1 ip 00007fe847079690 sp 00007fff5172b618 error 4 in libc-2.8.90.so[7fe846ff7000+169000]
Oct 20 19:10:41 frodo kdm[5950]: X server for display :0 terminated unexpectedly
[...]
Oct 20 19:10:45 frodo kdm_greet[9525]: Cannot open default user face
Oct 20 19:10:56 frodo kernel: [ 1078.167023] knotify4[9761]: segfault at 1 ip 00007ffb4bf9c690 sp 00007fff5664c538 error 4 in libc-2.8.90.so[7ffb4bf1a000+169000]
[...]
I can confirm this.
But for me knotify4 do not crash every time KDE starts but most of the times. When it crashes it seems to kill the kdm process so I'll return to the login screen.
[...] 8.90.so[ 7fe846ff7000+ 169000] 8.90.so[ 7ffb4bf1a000+ 169000]
Oct 20 19:09:21 frodo kdm_greet[8912]: Cannot open default user face
Oct 20 19:09:30 frodo kernel: [ 992.814251] knotify4[9148]: segfault at 1 ip 00007fe847079690 sp 00007fff5172b618 error 4 in libc-2.
Oct 20 19:10:41 frodo kdm[5950]: X server for display :0 terminated unexpectedly
[...]
Oct 20 19:10:45 frodo kdm_greet[9525]: Cannot open default user face
Oct 20 19:10:56 frodo kernel: [ 1078.167023] knotify4[9761]: segfault at 1 ip 00007ffb4bf9c690 sp 00007fff5664c538 error 4 in libc-2.
[...]