系统信息：
Ubuntu 18.04.1 LTS
NordVPN Version 2.0.0
我最近安装了以下nordvpn-release_1.0.0_all.deb内容这些说明。我能够使用 经由终端连接到 VPN 服务器nordvpn connect。但是，当我尝试断开连接（使用nordvpn disconnect）时，出现以下错误：
Failed to disconnect. Check logs for more information.
日志内容如下/var/log/nordvpn/daemon.log：
2018/11/19 16:02:55 Fetching servers
2018/11/19 16:02:55 Error while getting servers from database bucket does not exist
2018/11/19 16:02:55 Fetching configs
2018/11/19 16:02:55 Error while getting configs from database bucket does not exist
2018/11/19 16:02:55 Fetching insights
2018/11/19 16:02:55 Error while getting insights from database bucket does not exist
2018/11/19 16:02:56 Finished fetching insights
2018/11/19 16:02:56 Fetching servers
2018/11/19 16:02:56 Error while getting servers from database EOF
2018/11/19 16:03:00 Formatting servers
2018/11/19 16:03:00 Fetching insights
2018/11/19 16:03:00 Finished fetching insights from database
2018/11/19 16:03:00 Finished fetching servers
2018/11/19 16:03:00 Fetching configs
2018/11/19 16:03:00 Error while getting configs from database EOF
2018/11/19 16:03:10 Finished fetching configs
2018/11/19 16:03:11 Fetching insights
2018/11/19 16:03:11 Finished fetching insights from database
2018/11/19 16:03:23 Fetching insights
2018/11/19 16:03:23 Finished fetching insights from database
2018/11/19 16:03:23 Fetching insights
2018/11/19 16:03:23 Finished fetching insights from database
2018/11/19 16:03:28 Fetching servers
2018/11/19 16:03:28 Finished fetching servers from database
2018/11/19 16:03:30 Fetching insights
2018/11/19 16:03:30 Finished fetching insights from database
2018/11/19 16:03:30 OpenVPN 2.4.6 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [MH/PKTINFO] [AEAD] built on Oct 10 2018
2018/11/19 16:03:30 library versions: OpenSSL 1.1.1 11 Sep 2018, LZO 2.10
2018/11/19 16:03:30 MANAGEMENT: unix domain socket listening on /run/nordvpn-openvpn.sock
2018/11/19 16:03:30 Outgoing Control Channel Authentication: Using 512 bit message hash 'SHA512' for HMAC authentication
2018/11/19 16:03:30 Incoming Control Channel Authentication: Using 512 bit message hash 'SHA512' for HMAC authentication
2018/11/19 16:03:30 TCP/UDP: Preserving recently used remote address: [AF_INET]207.189.24.175:1194
2018/11/19 16:03:30 Socket Buffers: R=[212992->212992] S=[212992->212992]
2018/11/19 16:03:30 UDP link local: (not bound)
2018/11/19 16:03:30 UDP link remote: [AF_INET]207.189.24.175:1194
2018/11/19 16:03:30 MANAGEMENT: Client connected from /run/nordvpn-openvpn.sock
2018/11/19 16:03:30 MANAGEMENT: CMD 'hold release'
2018/11/19 16:03:30 MANAGEMENT: CMD 'hold off'
2018/11/19 16:03:30 TLS: Initial packet from [AF_INET]207.189.24.175:1194, sid=69b301e0 279dbbf9
2018/11/19 16:03:30 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this
2018/11/19 16:03:30 VERIFY OK: depth=2, C=PA, O=NordVPN, CN=NordVPN Root CA
2018/11/19 16:03:30 VERIFY OK: depth=1, C=PA, O=NordVPN, CN=NordVPN CA2
2018/11/19 16:03:30 VERIFY KU OK
2018/11/19 16:03:30 Validating certificate extended key usage
2018/11/19 16:03:30 ++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication
2018/11/19 16:03:30 VERIFY EKU OK
2018/11/19 16:03:30 VERIFY OK: depth=0, CN=us2185.nordvpn.com
2018/11/19 16:03:30 WARNING: 'link-mtu' is used inconsistently, local='link-mtu 1633', remote='link-mtu 1634'
2018/11/19 16:03:30 WARNING: 'comp-lzo' is present in remote config but missing in local config, remote='comp-lzo'
2018/11/19 16:03:30 Control Channel: TLSv1.2, cipher TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 2048 bit RSA
2018/11/19 16:03:30 [us2185.nordvpn.com] Peer Connection Initiated with [AF_INET]207.189.24.175:1194
2018/11/19 16:03:31 SENT CONTROL [us2185.nordvpn.com]: 'PUSH_REQUEST' (status=1)
2018/11/19 16:03:31 PUSH: Received control message: 'PUSH_REPLY,redirect-gateway def1,sndbuf 524288,rcvbuf 524288,dhcp-option DNS 103.86.96.100,dhcp-option DNS 103.86.99.100,comp-lzo no,route-gateway 10.8.8.1,topology subnet,ping 60,ping-restart 180,ifconfig 10.8.8.179 255.255.255.0,peer-id 15,cipher AES-256-GCM'
2018/11/19 16:03:31 OPTIONS IMPORT: timers and/or timeouts modified
2018/11/19 16:03:31 OPTIONS IMPORT: compression parms modified
2018/11/19 16:03:31 OPTIONS IMPORT: --sndbuf/--rcvbuf options modified
2018/11/19 16:03:31 Socket Buffers: R=[212992->425984] S=[212992->425984]
2018/11/19 16:03:31 OPTIONS IMPORT: --ifconfig/up options modified
2018/11/19 16:03:31 OPTIONS IMPORT: route options modified
2018/11/19 16:03:31 OPTIONS IMPORT: route-related options modified
2018/11/19 16:03:31 OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified
2018/11/19 16:03:31 OPTIONS IMPORT: peer-id set
2018/11/19 16:03:31 OPTIONS IMPORT: adjusting link_mtu to 1656
2018/11/19 16:03:31 OPTIONS IMPORT: data channel crypto options modified
2018/11/19 16:03:31 Data Channel: using negotiated cipher 'AES-256-GCM'
2018/11/19 16:03:31 Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
2018/11/19 16:03:31 Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
2018/11/19 16:03:31 TUN/TAP device tun0 opened
2018/11/19 16:03:31 TUN/TAP TX queue length set to 100
2018/11/19 16:03:31 do_ifconfig, tt->did_ifconfig_ipv6_setup=0
2018/11/19 16:03:31 /sbin/ifconfig tun0 10.8.8.179 netmask 255.255.255.0 mtu 1500 broadcast 10.8.8.255
2018/11/19 16:03:31 /sbin/route add -net 207.189.24.175 netmask 255.255.255.255 gw 192.168.0.1
2018/11/19 16:03:31 /sbin/route add -net 0.0.0.0 netmask 128.0.0.0 gw 10.8.8.1
2018/11/19 16:03:31 /sbin/route add -net 128.0.0.0 netmask 128.0.0.0 gw 10.8.8.1
2018/11/19 16:03:31 Initialization Sequence Completed
2018/11/19 16:03:31 Fetching insights
2018/11/19 16:03:31 Finished fetching insights from database
2018/11/19 16:03:35 Fetching insights
2018/11/19 16:03:35 Finished fetching insights from database
2018/11/19 16:03:35 /sbin/route del -net 207.189.24.175 netmask 255.255.255.255
2018/11/19 16:03:35 /sbin/route del -net 0.0.0.0 netmask 128.0.0.0
2018/11/19 16:03:35 /sbin/route del -net 128.0.0.0 netmask 128.0.0.0
2018/11/19 16:03:35 Closing TUN/TAP interface
2018/11/19 16:03:35 /sbin/ifconfig tun0 0.0.0.0
2018/11/19 16:03:35 SIGTERM[hard,] received, process exiting
2018/11/19 16:04:07 rpc.Serve: accept:accept unixpacket /run/nordvpn.sock: use of closed network connection
2018/11/19 16:04:45 Fetching servers
2018/11/19 16:04:45 Finished fetching servers from database
2018/11/19 16:04:45 Fetching configs
2018/11/19 16:04:50 Fetching insights
2018/11/19 16:04:50 Finished fetching insights from database
2018/11/19 16:04:50 Fetching servers
2018/11/19 16:04:50 Finished fetching servers from database
2018/11/19 16:04:50 Fetching configs
2018/11/19 16:04:55 Finished fetching configs from cache
2018/11/19 16:15:36 Fetching servers
2018/11/19 16:15:36 Finished fetching servers from database
2018/11/19 16:15:37 Fetching insights
2018/11/19 16:15:37 Finished fetching insights from database
2018/11/19 16:15:37 /var/lib/nordvpn/ovpn_udp/us1450.nordvpn.com.udp.ovpn file does not exist
2018/11/19 16:15:37 Fetching configs
2018/11/19 16:15:44 Finished fetching configs from cache
2018/11/19 16:15:45 OpenVPN 2.4.6 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [MH/PKTINFO] [AEAD] built on Oct 10 2018
2018/11/19 16:15:45 library versions: OpenSSL 1.1.1 11 Sep 2018, LZO 2.10
2018/11/19 16:15:45 MANAGEMENT: unix domain socket listening on /run/nordvpn-openvpn.sock
2018/11/19 16:15:45 WARNING: --ping should normally be used with --ping-restart or --ping-exit
2018/11/19 16:15:45 Outgoing Control Channel Authentication: Using 512 bit message hash 'SHA512' for HMAC authentication
2018/11/19 16:15:45 Incoming Control Channel Authentication: Using 512 bit message hash 'SHA512' for HMAC authentication
2018/11/19 16:15:45 TCP/UDP: Preserving recently used remote address: [AF_INET]38.132.115.221:1194
2018/11/19 16:15:45 Socket Buffers: R=[212992->212992] S=[212992->212992]
2018/11/19 16:15:45 UDP link local: (not bound)
2018/11/19 16:15:45 UDP link remote: [AF_INET]38.132.115.221:1194
2018/11/19 16:15:45 MANAGEMENT: Client connected from /run/nordvpn-openvpn.sock
2018/11/19 16:15:45 MANAGEMENT: CMD 'hold release'
2018/11/19 16:15:45 MANAGEMENT: CMD 'hold off'
2018/11/19 16:15:45 TLS: Initial packet from [AF_INET]38.132.115.221:1194, sid=9c7239fd 71622ac0
2018/11/19 16:15:45 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this
2018/11/19 16:15:46 VERIFY OK: depth=1, C=PA, ST=PA, L=Panama, O=NordVPN, OU=NordVPN, CN=us1450.nordvpn.com, name=NordVPN, [email protected]
2018/11/19 16:15:46 VERIFY KU OK
2018/11/19 16:15:46 Validating certificate extended key usage
2018/11/19 16:15:46 ++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication
2018/11/19 16:15:46 VERIFY EKU OK
2018/11/19 16:15:46 VERIFY OK: depth=0, C=PA, ST=PA, L=Panama, O=NordVPN, OU=NordVPN, CN=us1450.nordvpn.com, name=NordVPN, [email protected]
2018/11/19 16:15:46 Control Channel: TLSv1.2, cipher TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384, 2048 bit RSA
2018/11/19 16:15:46 [us1450.nordvpn.com] Peer Connection Initiated with [AF_INET]38.132.115.221:1194
2018/11/19 16:15:47 SENT CONTROL [us1450.nordvpn.com]: 'PUSH_REQUEST' (status=1)
2018/11/19 16:15:47 PUSH: Received control message: 'PUSH_REPLY,redirect-gateway def1,sndbuf 524288,rcvbuf 524288,dhcp-option DNS 103.86.96.100,dhcp-option DNS 103.86.99.100,comp-lzo no,route-gateway 10.8.8.1,topology subnet,ping 60,ping-restart 180,ifconfig 10.8.8.105 255.255.255.0,peer-id 16,cipher AES-256-GCM'
2018/11/19 16:15:47 OPTIONS IMPORT: timers and/or timeouts modified
2018/11/19 16:15:47 OPTIONS IMPORT: compression parms modified
2018/11/19 16:15:47 OPTIONS IMPORT: --sndbuf/--rcvbuf options modified
2018/11/19 16:15:47 Socket Buffers: R=[212992->425984] S=[212992->425984]
2018/11/19 16:15:47 OPTIONS IMPORT: --ifconfig/up options modified
2018/11/19 16:15:47 OPTIONS IMPORT: route options modified
2018/11/19 16:15:47 OPTIONS IMPORT: route-related options modified
2018/11/19 16:15:47 OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified
2018/11/19 16:15:47 OPTIONS IMPORT: peer-id set
2018/11/19 16:15:47 OPTIONS IMPORT: adjusting link_mtu to 1657
2018/11/19 16:15:47 OPTIONS IMPORT: data channel crypto options modified
2018/11/19 16:15:47 Data Channel: using negotiated cipher 'AES-256-GCM'
2018/11/19 16:15:47 Outgoing Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
2018/11/19 16:15:47 Incoming Data Channel: Cipher 'AES-256-GCM' initialized with 256 bit key
2018/11/19 16:15:47 TUN/TAP device tun0 opened
2018/11/19 16:15:47 TUN/TAP TX queue length set to 100
2018/11/19 16:15:47 do_ifconfig, tt->did_ifconfig_ipv6_setup=0
2018/11/19 16:15:47 /sbin/ifconfig tun0 10.8.8.105 netmask 255.255.255.0 mtu 1500 broadcast 10.8.8.255
2018/11/19 16:15:47 /sbin/route add -net 38.132.115.221 netmask 255.255.255.255 gw 192.168.0.1
2018/11/19 16:15:47 /sbin/route add -net 0.0.0.0 netmask 128.0.0.0 gw 10.8.8.1
2018/11/19 16:15:47 /sbin/route add -net 128.0.0.0 netmask 128.0.0.0 gw 10.8.8.1
2018/11/19 16:15:47 Initialization Sequence Completed
2018/11/19 16:15:47 Fetching insights
2018/11/19 16:15:47 Finished fetching insights from database
2018/11/19 16:17:01 Fetching insights
2018/11/19 16:17:01 Finished fetching insights from database
2018/11/19 16:17:01 MANAGEMENT: TCP recv error: Connection reset by peer
2018/11/19 16:17:01 MANAGEMENT: Client disconnected
2018/11/19 16:17:01 SIGTERM received, sending exit notification to peer
2018/11/19 16:17:04 /sbin/route del -net 38.132.115.221 netmask 255.255.255.255
2018/11/19 16:17:04 /sbin/route del -net 0.0.0.0 netmask 128.0.0.0
2018/11/19 16:17:04 /sbin/route del -net 128.0.0.0 netmask 128.0.0.0
2018/11/19 16:17:04 Closing TUN/TAP interface
2018/11/19 16:17:04 /sbin/ifconfig tun0 0.0.0.0
2018/11/19 16:17:04 SIGTERM[soft,exit-with-notification] received, process exiting
2018/11/19 16:20:06 rpc.Serve: accept:accept unixpacket /run/nordvpn.sock: use of closed network connection
2018/11/19 16:20:43 Fetching servers
2018/11/19 16:20:43 Finished fetching servers from database
2018/11/19 16:20:43 Fetching configs
2018/11/19 16:20:48 Fetching insights
2018/11/19 16:20:48 Finished fetching insights from database
2018/11/19 16:20:48 Fetching servers
2018/11/19 16:20:48 Finished fetching servers from database
2018/11/19 16:20:48 Fetching configs
2018/11/19 16:20:54 Finished fetching configs from cache