OpenVPN GUI 2.3.10 is work fine，When i update to 2.4.7，is can't connect to openvpn server
CA is Create by RouterBOARD

ovpn-server config

enabled: yes
port: 1194
mode: ip
netmask: 24
mac-address: FE:7E:41:06:67:CD
max-mtu: 1500
keepalive-timeout: 60
default-profile: opvn
certificate: myCa
require-client-certificate: yes
auth: sha1,md5,null
cipher: blowfish128,aes128,null

client.ovpn

client
dev tun
proto tcp
remote 192.168.0.1 1194
resolv-retry infinite
nobind
persist-key
persist-tun
ca ca.crt
cert client.crt
key client.key
;remote-cert-tls server
auth-user-pass
cipher AES-256-CBC
verb 3


OpenVPN GUI Log：

Fri Jun 07 10:10:58 2019 WARNING: No server certificate verification method has been enabled. See http://openvpn.net/howto.html#mitm for more info.
Fri Jun 07 10:10:58 2019 TCP/UDP: Preserving recently used remote address: [AF_INET]192.168.0.1:1194
Fri Jun 07 10:10:58 2019 Socket Buffers: R=[8192->8192] S=[8192->8192]
Fri Jun 07 10:10:58 2019 Attempting to establish TCP connection with [AF_INET]192.168.0.1:1194 [nonblock]
Fri Jun 07 10:10:58 2019 MANAGEMENT: >STATE:1559873458,TCP_CONNECT,,,,,,
Fri Jun 07 10:10:59 2019 TCP connection established with [AF_INET]192.168.0.1:1194
Fri Jun 07 10:10:59 2019 TCP_CLIENT link local: (not bound)
Fri Jun 07 10:10:59 2019 TCP_CLIENT link remote: [AF_INET]192.168.0.1:1194
Fri Jun 07 10:10:59 2019 MANAGEMENT: >STATE:1559873459,WAIT,,,,,,
Fri Jun 07 10:10:59 2019 MANAGEMENT: >STATE:1559873459,AUTH,,,,,,
Fri Jun 07 10:10:59 2019 TLS: Initial packet from [AF_INET]192.168.0.1:1194, sid=e595d8e8 c2feb850
Fri Jun 07 10:10:59 2019 VERIFY ERROR: depth=0, error=self signed certificate: CN=myCa
Fri Jun 07 10:10:59 2019 OpenSSL: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed
Fri Jun 07 10:10:59 2019 TLS_ERROR: BIO read tls_read_plaintext error
Fri Jun 07 10:10:59 2019 TLS Error: TLS object -> incoming plaintext read error
Fri Jun 07 10:10:59 2019 TLS Error: TLS handshake failed
Fri Jun 07 10:10:59 2019 Fatal TLS error (check_tls_errors_co), restarting
Fri Jun 07 10:10:59 2019 SIGUSR1[soft,tls-error] received, process restarting
Fri Jun 07 10:10:59 2019 MANAGEMENT: >STATE:1559873459,RECONNECTING,tls-error,,,,,
Fri Jun 07 10:10:59 2019 Restart pause, 5 second(s)

Router Log：

Jun/07/2019 10:11:44 ovpn,info TCP connection established from 192.168.0.8
Jun/07/2019 10:11:44 ovpn,debug,packet sent P_CONTROL_HARD_RESET_SERVER_V2 kid=0 sid=e595d8e8c2feb850 pid=0 DATA len=0
Jun/07/2019 10:11:45 ovpn,debug,packet rcvd P_CONTROL_HARD_RESET_CLIENT_V2 kid=0 sid=46fc905acdeee429 pid=0 DATA len=0
Jun/07/2019 10:11:45 ovpn,debug,packet sent P_ACK kid=0 sid=e595d8e8c2feb850 [0 sid=46fc905acdeee429] DATA len=0
Jun/07/2019 10:11:45 ovpn,debug,packet rcvd P_CONTROL_HARD_RESET_CLIENT_V2 kid=0 sid=46fc905acdeee429 [0 sid=e595d8e8c2feb850] pid=0 DATA len=0
Jun/07/2019 10:11:45 ovpn,debug,error,,,,,,,,,l2tp,info,,debug,,,critical,,,,,,,,,,,,,warning duplicate packet, dropping
Jun/07/2019 10:11:45 ovpn,debug,packet rcvd P_CONTROL kid=0 sid=46fc905acdeee429 pid=1 DATA len=160
Jun/07/2019 10:11:45 ovpn,debug,packet sent P_ACK kid=0 sid=e595d8e8c2feb850 [1 sid=46fc905acdeee429] DATA len=0
Jun/07/2019 10:11:46 ovpn,debug,packet sent P_CONTROL kid=0 sid=e595d8e8c2feb850 pid=1 DATA len=1400
Jun/07/2019 10:11:46 ovpn,debug,packet sent P_CONTROL kid=0 sid=e595d8e8c2feb850 pid=2 DATA len=376
Jun/07/2019 10:11:46 ovpn,debug <192.168.0.8>: disconnected <peer disconnected>

I use OpenVPN GUI easy-rsa Building Certificates and Keys,now is working in OpenVPN GUI 2.4.7，hope can help some people

Did you read your Clients log file?

Fri Jun 07 10:10:59 2019 VERIFY ERROR: depth=0, error=self signed certificate: CN=myCa
Fri Jun 07 10:10:59 2019 OpenSSL: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed

You have set myCa as server certificate on your mikrotik instead of the server certificate..

Did you read your Clients log file?

Fri Jun 07 10:10:59 2019 VERIFY ERROR: depth=0, error=self signed certificate: CN=myCa
Fri Jun 07 10:10:59 2019 OpenSSL: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed

You have set myCa as server certificate on your mikrotik instead of the server certificate..

I set server certificate on my mikrotik ，but the same can't connection.Same configuration with OpenVPN GUI 2.3.10 is work

Maybe you need to try another VPN service? I use OpenVPN GUI 2.4.7 and it works Just great.
VPNs with router support
I hope its not a spam, if so, please delete my post. Cheers

I hope its not a spam, if so, please delete my post. Cheers

I think it is rather a misunderstanding on your side of what the OP's problem is.

There are two uses of VPN:

1. the one for which VPNs were originaly invented, i.e. to allow encrypted access to your own networks via internet,
2. the one which most home users know as VPN today, which is to hide the pages you actually surf from your ISP and/or the authorities, or to hide your actual IP address from the services which apply geographical policing (so you cannot use your Netflix subscription while you stay in another country).

As the OP claims an issue where Mikrotik is on the server side, he most likely deals with case a., so replacing the VPN provider is not an option. Theoretically, he may have a Mikrotik running at home to be able to watch Netflix while abroad, but in this case a public VPN service may still not be a sufficient substitution as the content provider guys are no idiots either so they often block access from IP addresses known to belong to public VPN providers.

Maybe you need to try another VPN service? I use OpenVPN GUI 2.4.7 and it works Just great.
VPNs with router support
I hope its not a spam, if so, please delete my post. Cheers

sorry anyone，i find the Reason，is my creat certificate Method is wrong.

ovpn-server config:
cipher: blowfish128,aes128,null

client.ovpn:
cipher AES-256-CBC

The parameters must have common values,
such as 'cipher=aes256' for the server and 'cipher AES256' for the client.