Comment 3 for bug 1605807

By the way this may also be hardware problems, see the following messages from your system logs:

Jul 22 23:06:36 ubuntu partman: mke2fs 1.42.13 (17-May-2015)
Jul 22 23:06:36 ubuntu ubiquity[28638]: log-output -t ubiquity setxkbmap -model pc105 -layout cz -option -option lv3:ralt_switch
Jul 22 23:07:00 ubuntu ubiquity[28638]: log-output -t ubiquity setxkbmap -model pc105 -layout cz -option -option lv3:ralt_switch
Jul 22 23:07:00 ubuntu ubiquity[28638]: switched to page console_setup
Jul 22 23:07:01 ubuntu ubiquity[28638]: log-output -t ubiquity setxkbmap -model pc105 -layout cz -option -option lv3:ralt_switch
Jul 22 23:07:03 ubuntu ubiquity: Your console font configuration will be updated the next time your system
Jul 22 23:07:03 ubuntu ubiquity: boots. If you want to update it now, run 'setupcon' from a virtual console.
Jul 22 23:07:03 ubuntu ubiquity[28638]: log-output -t ubiquity setxkbmap -model pc105 -layout cz -option
Jul 22 23:07:03 ubuntu ubiquity[28638]: debconffilter_done: ubi-console-setup (current: ubi-console-setup)
Jul 22 23:07:03 ubuntu ubiquity[28638]: Step_before = stepKeyboardConf
Jul 22 23:07:03 ubuntu ubiquity[28638]: switched to page usersetup
Jul 22 23:07:04 ubuntu partman: mke2fs 1.42.13 (17-May-2015)
Jul 22 23:07:13 ubuntu kernel: [64461.108242] ------------[ cut here ]------------
Jul 22 23:07:13 ubuntu kernel: [64461.108281] WARNING: CPU: 0 PID: 10984 at /build/linux-xK5wks/linux-4.4.0/net/wireless/sme.c:850 cfg80211_roamed+0x7f/0x90 [cfg80211]()
Jul 22 23:07:13 ubuntu kernel: [64461.108283] Modules linked in: dm_crypt ufs qnx4 hfsplus hfs minix ntfs msdos btrfs xor raid6_pq ipt_MASQUERADE nf_nat_masquerade_ipv4 xt_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp iptable_filter nf_nat_h323 nf_conntrack_h323 nf_nat_pptp nf_nat_proto_gre nf_conntrack_pptp nf_conntrack_proto_gre nf_nat_tftp nf_conntrack_tftp nf_nat_sip nf_conntrack_sip nf_nat_irc nf_conntrack_irc nf_nat_ftp nf_conntrack_ftp iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack ip_tables x_tables wl(POE) rfcomm option usb_wwan usbserial bnep mac80211 coretemp kvm_intel cfg80211 snd_hda_codec_realtek snd_hda_codec_generic joydev kvm applesmc btusb btrtl btbcm btintel input_polldev snd_hda_intel uvcvideo bluetooth irqbypass videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 snd_hda_codec videobuf2_core v4l2_common videodev snd_hda_core shpchp media input_leds snd_hwdep bcm5974 snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq sbs snd_seq_device apple_gmux snd_timer snd acpi_als kfifo_buf sbshc apple_bl industrialio soundcore i2c_nforce2 mac_hid parport_pc ppdev lp parport autofs4 overlay nls_utf8 isofs nls_iso8859_1 jfs xfs libcrc32c reiserfs hid_apple dm_mirror dm_region_hash dm_log hid_generic hid_appleir usbhid hid uas usb_storage nouveau mxm_wmi wmi video i2c_algo_bit ttm drm_kms_helper syscopyarea firewire_ohci sysfillrect firewire_core crc_itu_t sysimgblt fb_sys_fops drm forcedeth ahci libahci fjes [last unloaded: bcma]
Jul 22 23:07:13 ubuntu kernel: [64461.108394] CPU: 0 PID: 10984 Comm: wl_event_handle Tainted: P W OE 4.4.0-31-generic #50-Ubuntu
Jul 22 23:07:13 ubuntu kernel: [64461.108396] Hardware name: Apple Inc. MacBookPro5,1/Mac-F42D86C8, BIOS MBP51.88Z.007E.B06.1202061253 02/06/12
Jul 22 23:07:13 ubuntu kernel: [64461.108399] c2acd967 71f9f6dc 00000286 f1d7beac c23a689f 00000000 f90147e0 f1d7bedc
Jul 22 23:07:13 ubuntu kernel: [64461.108404] c2070317 c29c0588 00000000 00002ae8 f90147e0 00000352 f8ff399f f8ff399f
Jul 22 23:07:13 ubuntu kernel: [64461.108408] e631d000 f5642c44 e631d000 f1d7beec c2070422 00000009 00000000 f1d7bf0c
Jul 22 23:07:13 ubuntu kernel: [64461.108413] Call Trace:
Jul 22 23:07:13 ubuntu kernel: [64461.108419] [<c23a689f>] dump_stack+0x58/0x79
Jul 22 23:07:13 ubuntu kernel: [64461.108424] [<c2070317>] warn_slowpath_common+0x87/0xc0
Jul 22 23:07:13 ubuntu kernel: [64461.108442] [<f8ff399f>] ? cfg80211_roamed+0x7f/0x90 [cfg80211]
Jul 22 23:07:13 ubuntu kernel: [64461.108459] [<f8ff399f>] ? cfg80211_roamed+0x7f/0x90 [cfg80211]
Jul 22 23:07:13 ubuntu kernel: [64461.108462] [<c2070422>] warn_slowpath_null+0x22/0x30
Jul 22 23:07:13 ubuntu kernel: [64461.108480] [<f8ff399f>] cfg80211_roamed+0x7f/0x90 [cfg80211]
Jul 22 23:07:13 ubuntu kernel: [64461.108534] [<fd8a2206>] wl_notify_roaming_status+0xb6/0x130 [wl]
Jul 22 23:07:13 ubuntu kernel: [64461.108575] [<fd8a2150>] ? wl_get_assoc_ies+0x240/0x240 [wl]
Jul 22 23:07:13 ubuntu kernel: [64461.108615] [<fd8a183f>] wl_event_handler+0x5f/0x1d0 [wl]
Jul 22 23:07:13 ubuntu kernel: [64461.108656] [<fd8a17e0>] ? wl_notify_scan_status+0x320/0x320 [wl]
Jul 22 23:07:13 ubuntu kernel: [64461.108660] [<c208cf46>] kthread+0xa6/0xc0
Jul 22 23:07:13 ubuntu kernel: [64461.108664] [<c27b1f49>] ret_from_kernel_thread+0x21/0x38
Jul 22 23:07:13 ubuntu kernel: [64461.108667] [<c208cea0>] ? kthread_create_on_node+0x170/0x170
Jul 22 23:07:13 ubuntu kernel: [64461.108669] ---[ end trace 7447eea3275f1931 ]---
Jul 22 23:07:13 ubuntu wpa_supplicant[10997]: wls3: WPA: EAPOL-Key Replay Counter did not increase - dropping packet
Jul 22 23:07:14 ubuntu wpa_supplicant[10997]: wls3: WPA: EAPOL-Key Replay Counter did not increase - dropping packet
Jul 22 23:07:15 ubuntu NetworkManager[3230]: <info> [1469228835.0584] device (wls3): supplicant interface state: completed -> 4-way handshake
Jul 22 23:07:15 ubuntu wpa_supplicant[10997]: wls3: WPA: Key negotiation completed with f0:79:59:78:e6:18 [PTK=CCMP GTK=CCMP]
Jul 22 23:07:15 ubuntu NetworkManager[3230]: <info> [1469228835.0753] device (wls3): supplicant interface state: 4-way handshake -> completed
Jul 22 23:07:45 ubuntu kernel: [64493.925269] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: errors=remount-ro
Jul 22 23:07:45 ubuntu kernel: [64493.947436] EXT4-fs (sdc2): mounting ext2 file system using the ext4 subsystem
Jul 22 23:07:45 ubuntu kernel: [64493.983471] EXT4-fs (sdc2): mounted filesystem without journal. Opts: (null)
...
Jul 22 23:15:14 ubuntu kernel: [64942.125873] usb 1-1: USB disconnect, device number 8
Jul 22 23:15:14 ubuntu kernel: [64942.126133] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
Jul 22 23:15:14 ubuntu kernel: [64942.126152] option 1-1:1.0: device disconnected
Jul 22 23:15:14 ubuntu kernel: [64942.127484] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
Jul 22 23:15:14 ubuntu kernel: [64942.127500] option 1-1:1.1: device disconnected
Jul 22 23:15:14 ubuntu kernel: [64942.136055] sd 18:0:0:0: [sdc] tag#0 FAILED Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
Jul 22 23:15:14 ubuntu kernel: [64942.136062] sd 18:0:0:0: [sdc] tag#0 CDB: Write(10) 2a 00 00 2e 44 b0 00 00 f0 00
Jul 22 23:15:14 ubuntu kernel: [64942.136065] blk_update_request: I/O error, dev sdc, sector 3032240
Jul 22 23:15:14 ubuntu kernel: [64942.136074] blk_update_request: I/O error, dev sdc, sector 0
Jul 22 23:15:14 ubuntu kernel: [64942.136105] EXT4-fs warning (device dm-0): ext4_end_bio:329: I/O error -5 writing to inode 923173 (offset 4194304 size 4194304 starting block 122624)
Jul 22 23:15:14 ubuntu kernel: [64942.136109] Buffer I/O error on device dm-0, logical block 122624
Jul 22 23:15:14 ubuntu kernel: [64942.136113] Buffer I/O error on device dm-0, logical block 122625
Jul 22 23:15:14 ubuntu kernel: [64942.136115] Buffer I/O error on device dm-0, logical block 122626
Jul 22 23:15:14 ubuntu kernel: [64942.136117] Buffer I/O error on device dm-0, logical block 122627
Jul 22 23:15:14 ubuntu kernel: [64942.136119] Buffer I/O error on device dm-0, logical block 122628
Jul 22 23:15:14 ubuntu kernel: [64942.136121] Buffer I/O error on device dm-0, logical block 122629
Jul 22 23:15:14 ubuntu kernel: [64942.136123] Buffer I/O error on device dm-0, logical block 122630
Jul 22 23:15:14 ubuntu kernel: [64942.136125] Buffer I/O error on device dm-0, logical block 122631
Jul 22 23:15:14 ubuntu kernel: [64942.136127] Buffer I/O error on device dm-0, logical block 122632
Jul 22 23:15:14 ubuntu kernel: [64942.136130] Buffer I/O error on device dm-0, logical block 122633
Jul 22 23:15:14 ubuntu kernel: [64942.136318] EXT4-fs warning (device dm-0): ext4_end_bio:329: I/O error -5 writing to inode 923173 (offset 8388608 size 4194304 starting block 122880)
Jul 22 23:15:14 ubuntu kernel: [64942.136505] EXT4-fs warning (device dm-0): ext4_end_bio:329: I/O error -5 writing to inode 923173 (offset 8388608 size 4194304 starting block 123136)