After connecting the mouse kde is stop. After logout and login in kde, kde working normally. dmesg command show kactivitymanage[1370]: segfault at 7fb5e4127cd0 ip 00007fb5e40d11b1 sp 00007fffbf3b08f8 error 4 in libQt5Sql.so.5.4.2[7fb5e40bd000+3f000]. This occurs several times per day.
[12984.496939] usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [12984.496945] usb 2-1.3: Product: USB Mouse [12984.496949] usb 2-1.3: Manufacturer: A4Tech [12984.502659] input: A4Tech USB Mouse as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.3/2-1.3:1.0/0003:09DA:000A.0004/input/input17 [12984.556012] a4tech 0003:09DA:000A.0004: input,hidraw0: USB HID v1.10 Mouse [A4Tech USB Mouse] on usb-0000:00:1d.0-1.3/input0 [13090.905902] show_signal_msg: 21 callbacks suppressed [13090.905909] kactivitymanage[1370]: segfault at 7fb5e4127cd0 ip 00007fb5e40d11b1 sp 00007fffbf3b08f8 error 4 in libQt5Sql.so.5.4.2[7fb5e40bd000+3f000]
See bug 355478 comment #1.
The session crash pulls the kactivitymanagerd, not the vice versa. It seems like a driver issue that rubs X11 the wrong way and it crashes. As for the sql issue, it is a bug in qt which will hopefully get fixed soon, or I'll have to add a work-around in kamd. *** This bug has been marked as a duplicate of bug 348194 ***