Fail to connect from Windows and iOS client

[CyanideCentral]

My VPN is set up on a DigitalOcean Ubuntu VPS, and connection failure has lasted for several days. I've already tried reinstalling the VPN but it's no use.

Pluto log:
Oct 17 03:11:38 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #1: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:11:38 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #1: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:11:38 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #1: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:11:41 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #2: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:11:41 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #2: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:11:41 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #2: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:11:44 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #3: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:11:44 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #3: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:11:44 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #3: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:11:47 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #4: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:11:47 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #4: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:11:47 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #4: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #5: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #5: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #5: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: packet from *.*.*.*:46297: not enough room in input packet for ISAKMP Message (remain=0, sd->size=28)
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: packet from *.*.*.*:46297: Received packet with mangled IKE header - dropped
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: packet from *.*.*.*:46297: not enough room in input packet for ISAKMP Message (remain=0, sd->size=28)
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: packet from *.*.*.*:46297: Received packet with mangled IKE header - dropped
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: packet from *.*.*.*:46297: not enough room in input packet for ISAKMP Message (remain=0, sd->size=28)
Oct 17 03:14:55 ubuntu-LYR0 pluto[15434]: packet from *.*.*.*:46297: Received packet with mangled IKE header - dropped
Oct 17 03:14:58 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #6: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:14:58 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #6: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:14:58 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #6: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:15:01 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #7: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:15:01 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #7: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:15:01 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #7: STATE_MAIN_R1: sent MR1, expecting MI2
Oct 17 03:15:04 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #8: responding to Main Mode from unknown peer *.*.*.*
Oct 17 03:15:04 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #8: transition from state STATE_MAIN_R0 to state STATE_MAIN_R1
Oct 17 03:15:04 ubuntu-LYR0 pluto[15434]: "l2tp-psk"[1] *.*.*.* #8: STATE_MAIN_R1: sent MR1, expecting MI2

[hwdsl2]

@CyanideCentral Hello! Currently there is significant VPN blocking by the firewall for people in China. Try a new Droplet with a different IP, a new DigitalOcean region, or another VPS provider. You may also try Shadowsocks.