scan failed

ubuntu version:
 lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.1 LTS
Release: 14.04
Codename: trusty

after plugin Kworld 330U usb tuner,
dmesg | grep em28xx
[1027855.535570] em28xx: New device USB 2883 Device @ 480 Mbps (eb1a:a316, interface 0, class 0)
[1027855.535581] em28xx: Audio interface 0 found (Vendor Class)
[1027855.535586] em28xx: Video interface 0 found: isoc
[1027855.535590] em28xx: DVB interface 0 found: isoc
[1027855.535702] em28xx: chip ID is em2882/3
[1027857.525844] usbcore: registered new interface driver em28xx
[1027857.585276] em28xx-audio.c: probing for em28xx Audio Vendor Class
[1027857.585287] em28xx-audio.c: Copyright (C) 2006 Markus Rechberger
[1027857.585291] em28xx-audio.c: Copyright (C) 2007-2011 Mauro Carvalho Chehab
[1027857.912936] em2882/3 #0: Successfully loaded em28xx-dvb
asus@asus-900:~$ dmesg | grep em28xx
[1027855.535570] em28xx: New device USB 2883 Device @ 480 Mbps (eb1a:a316, interface 0, class 0)
[1027855.535581] em28xx: Audio interface 0 found (Vendor Class)
[1027855.535586] em28xx: Video interface 0 found: isoc
[1027855.535590] em28xx: DVB interface 0 found: isoc
[1027855.535702] em28xx: chip ID is em2882/3
[1027857.525844] usbcore: registered new interface driver em28xx
[1027857.585276] em28xx-audio.c: probing for em28xx Audio Vendor Class
[1027857.585287] em28xx-audio.c: Copyright (C) 2006 Markus Rechberger
[1027857.585291] em28xx-audio.c: Copyright (C) 2007-2011 Mauro Carvalho Chehab
[1027857.912936] em2882/3 #0: Successfully loaded em28xx-dvb

do scan:
scan /usr/share/dvb/atsc/us-ATSC-center-frequencies-8VSB
...

scan failed and check errors:

dmesg | grep -i error
[ 6.692124] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro
[ 9.386597] [drm:i915_stolen_to_physical] *ERROR* conflict detected with stolen region: [0x3f800000 - 0x3ffc0000]
[ 12.704293] sd 5:0:0:0: [sde] Unhandled error code
[ 12.704312] Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
[ 12.704344] end_request: I/O error, dev sde, sector 312581632
[ 12.704467] Buffer I/O error on device sde, logical block 39072704
[ 12.716091] sd 5:0:0:0: [sde] Unhandled error code
[ 12.716152] end_request: I/O error, dev sde, sector 312581632
[ 12.716275] Buffer I/O error on device sde, logical block 39072704
[ 169.703524] xc2028 6-0061: Error on line 1299: -19
[ 169.973526] xc2028 6-0061: Error on line 1299: -19
[ 586.550853] xc2028 6-0061: Error on line 1299: -19