大家好，希望你们都很好，这是我在论坛上的第一篇帖子。
我在使用 openvpn 时遇到一些问题，由于严重错误而退出。我使用 frootvpn，这是我的终端。
sudo openvpn --config serverfile.ovpn
[sudo] password for server:
Wed Oct 3 17:42:47 2018 OpenVPN 2.4.4 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on Sep 5 2018
Wed Oct 3 17:42:47 2018 library versions: OpenSSL 1.1.0g 2 Nov 2017, LZO 2.08
Enter Auth Username: username
Enter Auth Password: ***
Wed Oct 3 17:42:54 2018 TCP/UDP: Preserving recently used remote address: [AF_INET]103.248.23.224:1195
Wed Oct 3 17:42:54 2018 UDP link local: (not bound)
Wed Oct 3 17:42:54 2018 UDP link remote: [AF_INET]103.248.23.224:1195
Wed Oct 3 17:42:57 2018 [server] Peer Connection Initiated with [AF_INET]103.248.23.224:1195
Wed Oct 3 17:42:58 2018 Option 'explicit-exit-notify' in [PUSH-OPTIONS]:4 is ignored by previous <connection> blocks
Wed Oct 3 17:42:58 2018 Options error: Unrecognized option or missing or extra parameter(s) in [PUSH-OPTIONS]:5: block-outside-dns (2.4.4)
Wed Oct 3 17:42:58 2018 TUN/TAP device tun0 opened
Wed Oct 3 17:42:58 2018 do_ifconfig, tt->did_ifconfig_ipv6_setup=0
Wed Oct 3 17:42:58 2018 /sbin/ip link set dev tun0 up mtu 1500
Wed Oct 3 17:42:58 2018 /sbin/ip addr add dev tun0 10.10.60.130/26 broadcast 10.10.60.191
Wed Oct 3 17:42:58 2018 Initialization Sequence Completed
Enter Auth Username:
Failed to query password: Timer expired
Enter Auth Password:
Failed to query password: Timer expired
Wed Oct 3 18:45:58 2018 ERROR: Failed retrieving username or password
Wed Oct 3 18:45:58 2018 Exiting due to fatal error
Wed Oct 3 18:45:58 2018 /sbin/ip addr del dev tun0 10.10.60.130/26
它可以工作一段时间，但随后就退出了。
知道我在这里做错了什么吗？