SSL VPN not connecting

Hello,

I have setup the SSL VPN but I cannot connect to it. When i try, the connection resets. Some logs perhaps might help below. Accessing the User portal doesn't seem to be an issue so i don't know what might be wrong.

Thanks in advance!

Sidenote: IPs and usernames have been removed and replaced with {}

On the UTM:

vpn-1 openvpn[9336]: {CLIENT IP ADDRESS}:24784 SIGUSR1[soft,connection-reset] received, client-instance restarting
vpn-1 openvpn[9336]: TCP connection established with [AF_INET]{ISP IP ADDRESS}:60864 (via [AF_INET]{SERVER IP ADDRESS}:443)
vpn-1 openvpn[9336]: {ISP IP ADDRESS}:60864 Non-OpenVPN client protocol detected
vpn-1 openvpn[9336]: {ISP IP ADDRESS}:60864 SIGTERM[soft,port-share-redirect] received, client-instance exiting
vpn-1 openvpn[9336]: TCP connection established with [AF_INET]{ISP ANOTHER IP ADDRESS}:50802 (via [AF_INET]{SERVER IP ADDRESS}:443)
vpn-1 openvpn[9336]: {ISP ANOTHER IP ADDRESS}:50802 Non-OpenVPN client protocol detected
vpn-1 openvpn[9336]: {ISP ANOTHER IP ADDRESS}:50802 SIGTERM[soft,port-share-redirect] received, client-instance exiting
vpn-1 openvpn[9336]: MANAGEMENT: Client connected from /var/run/openvpn_mgmt
vpn-1 openvpn[9336]: MANAGEMENT: CMD 'status -1'
vpn-1 openvpn[9336]: MANAGEMENT: Client disconnected
vpn-1 openvpn[9336]: TCP connection established with [AF_INET]{CLIENT IP ADDRESS}:28930 (via [AF_INET]{SERVER IP ADDRESS}:443)
vpn-1 openvpn[9336]: {CLIENT IP ADDRESS}:28930 TLS: Initial packet from [AF_INET]{CLIENT IP ADDRESS}:28930 (via [AF_INET]{SERVER IP ADDRESS}:443), sid=f09b225d 08e16e4c
vpn-1 openvpn[9336]: {CLIENT IP ADDRESS}:28930 Connection reset, restarting [-1]
vpn-1 openvpn[9336]: {CLIENT IP ADDRESS}:28930 SIGUSR1[soft,connection-reset] received, client-instance restarting

Client Side 1:

OpenVPN 2.3.8 i686-w64-mingw32 [SSL (OpenSSL)] [LZO] [IPv6] built on Jun 25 2016
library versions: OpenSSL 1.0.1t 3 May 2016, LZO 2.09
Enter Management Password:
MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25340
Need hold release from management interface, waiting...
MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25340
MANAGEMENT: CMD 'state on'
MANAGEMENT: CMD 'log all on'
MANAGEMENT: CMD 'hold off'
MANAGEMENT: CMD 'hold release'
MANAGEMENT: CMD 'username "Auth" "{USER}"'
MANAGEMENT: CMD 'password [...]'
Socket Buffers: R=[65536->65536] S=[65536->65536]
MANAGEMENT: >STATE:1482303961,RESOLVE,,,,,,
Attempting to establish TCP connection with [AF_INET]{SERVER IP ADDRESS}:443 [nonblock]
MANAGEMENT: >STATE:1482303961,TCP_CONNECT,,,,,,
TCP connection established with [AF_INET]{SERVER IP ADDRESS}:443
TCPv4_CLIENT link local: [undef]
TCPv4_CLIENT link remote: [AF_INET]{SERVER IP ADDRESS}:443
MANAGEMENT: >STATE:1482303962,WAIT,,,,,,
MANAGEMENT: >STATE:1482303962,AUTH,,,,,,
TLS: Initial packet from [AF_INET]{SERVER IP ADDRESS}:443, sid=280f400d fe17ec8c
WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this
VERIFY ERROR: depth=1, error=unable to get issuer certificate: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
TLS_ERROR: BIO read tls_read_plaintext error: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
TLS Error: TLS object -> incoming plaintext read error
TLS Error: TLS handshake failed
Fatal TLS error (check_tls_errors_co), restarting
SIGUSR1[soft,tls-error] received, process restarting
MANAGEMENT: >STATE:1482303963,RECONNECTING,tls-error,,,,,
Restart pause, 5 second(s)
Socket Buffers: R=[65536->65536] S=[65536->65536]
MANAGEMENT: >STATE:1482303968,RESOLVE,,,,,,
Attempting to establish TCP connection with [AF_INET]{SERVER IP ADDRESS}:443 [nonblock]
MANAGEMENT: >STATE:1482303968,TCP_CONNECT,,,,,,
TCP connection established with [AF_INET]{SERVER IP ADDRESS}:443
TCPv4_CLIENT link local: [undef]
TCPv4_CLIENT link remote: [AF_INET]{SERVER IP ADDRESS}:443
MANAGEMENT: >STATE:1482303969,WAIT,,,,,,
MANAGEMENT: >STATE:1482303969,AUTH,,,,,,
TLS: Initial packet from [AF_INET]{SERVER IP ADDRESS}:443, sid=ecb6e4fa 5ea600ee
VERIFY ERROR: depth=1, error=unable to get issuer certificate: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
TLS_ERROR: BIO read tls_read_plaintext error: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
TLS Error: TLS object -> incoming plaintext read error
TLS Error: TLS handshake failed
Fatal TLS error (check_tls_errors_co), restarting
SIGUSR1[soft,tls-error] received, process restarting
MANAGEMENT: >STATE:1482303969,RECONNECTING,tls-error,,,,,
Restart pause, 5 second(s)
Socket Buffers: R=[65536->65536] S=[65536->65536]
MANAGEMENT: >STATE:1482303974,RESOLVE,,,,,,
Attempting to establish TCP connection with [AF_INET]{SERVER IP ADDRESS}:443 [nonblock]
MANAGEMENT: >STATE:1482303974,TCP_CONNECT,,,,,,
SIGTERM[hard,init_instance] received, process exiting
MANAGEMENT: >STATE:1482303975,EXITING,init_instance,,,,,

Client Side 2:

OpenVPN 2.3.8 i686-w64-mingw32 [SSL (OpenSSL)] [LZO] [IPv6] built on Jun 25 2016
library versions: OpenSSL 1.0.1t 3 May 2016, LZO 2.09
Enter Management Password:
MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25341
Need hold release from management interface, waiting...
MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25341
MANAGEMENT: CMD 'state on'
MANAGEMENT: CMD 'log all on'
MANAGEMENT: CMD 'hold off'
MANAGEMENT: CMD 'hold release'
MANAGEMENT: CMD 'username "Auth" "a-vasileiosg"'
MANAGEMENT: CMD 'password [...]'
Socket Buffers: R=[65536->65536] S=[65536->65536]
MANAGEMENT: >STATE:1482304343,RESOLVE,,,,,,
Attempting to establish TCP connection with [AF_INET]{SERVER IP ADDRESS}:443 [nonblock]
MANAGEMENT: >STATE:1482304343,TCP_CONNECT,,,,,,
TCP connection established with [AF_INET]{SERVER IP ADDRESS}:443
TCPv4_CLIENT link local: [undef]
TCPv4_CLIENT link remote: [AF_INET]{SERVER IP ADDRESS}:443
MANAGEMENT: >STATE:1482304344,WAIT,,,,,,
Connection reset, restarting [-1]
SIGUSR1[soft,connection-reset] received, process restarting
MANAGEMENT: >STATE:1482304345,RECONNECTING,connection-reset,,,,,
Restart pause, 5 second(s)
Socket Buffers: R=[65536->65536] S=[65536->65536]
MANAGEMENT: >STATE:1482304350,RESOLVE,,,,,,
Attempting to establish TCP connection with [AF_INET]{SERVER IP ADDRESS}:443 [nonblock]
MANAGEMENT: >STATE:1482304350,TCP_CONNECT,,,,,,
TCP connection established with [AF_INET]{SERVER IP ADDRESS}:443
TCPv4_CLIENT link local: [undef]
TCPv4_CLIENT link remote: [AF_INET]{SERVER IP ADDRESS}:443
MANAGEMENT: >STATE:1482304351,WAIT,,,,,,
SIGTERM[hard,] received, process exiting
MANAGEMENT: >STATE:1482304351,EXITING,SIGTERM,,,,,