OpenVPN route addition failed using service

[genesis_mp]

Hi there,

we have some problems with our OpenVPN Client. We got this error when we connect our Clients. Client Version on Packages Manager is 1.4.14 and the export Version is (2.4.4-Ix01). The Client is connecting and it seems to work but it doesn´t works at all. This configuration worked before and without an update or something else, except Windows and Driver Updates on the clients this error occurs. It has the same error on more clients.

In the log view this error seems to be the problem:

ROUTE: route addition failed using service: Falscher Parameter. [status=87 if_index=20]

Here is the complete log:

Wed Jul 04 10:38:59 2018 OpenVPN 2.4.4 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [LZ4] [PKCS11] [AEAD] built on Sep 26 2017
Wed Jul 04 10:38:59 2018 Windows version 6.2 (Windows 8 or greater) 64bit
Wed Jul 04 10:38:59 2018 library versions: OpenSSL 1.0.2l 25 May 2017, LZO 2.10
Enter Management Password:
Wed Jul 04 11:13:36 2018 TCP/UDP: Preserving recently used remote address: [AF_INET]46.xx.xx.xx:1194
Wed Jul 04 11:13:36 2018 UDP link local (bound): [AF_INET][undef]:1194
Wed Jul 04 11:13:36 2018 UDP link remote: [AF_INET]46.xx.xx.xxx:1194
Wed Jul 04 11:13:36 2018 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this
Wed Jul 04 11:13:36 2018 [fw-remote-vpn1.domain.de] Peer Connection Initiated with [AF_INET]46.xx.xx.xx:1194
Wed Jul 04 11:13:38 2018 open_tun
Wed Jul 04 11:13:38 2018 TAP-WIN32 device [Ethernet 2] opened: \.\Global{C4E784BD-1C82-436E-A8FD-0E03941211E9}.tap
Wed Jul 04 11:13:38 2018 Notified TAP-Windows driver to set a DHCP IP/netmask of 10.10.220.86/255.255.255.252 on interface {C4E784BD-1C82-436E-A8FD-0E03941211E9} [DHCP-serv: 10.10.220.85, lease-time: 31536000]
Wed Jul 04 11:13:38 2018 Successful ARP Flush on interface [20] {C4E784BD-1C82-436E-A8FD-0E03941211E9}
Wed Jul 04 11:13:38 2018 do_ifconfig, tt->did_ifconfig_ipv6_setup=0
Wed Jul 04 11:13:43 2018 ROUTE: route addition failed using service: Falscher Parameter. [status=87 if_index=20]
Wed Jul 04 11:13:43 2018 Initialization Sequence Completed
Wed Jul 04 11:13:43 2018 Register_dns request sent to the service

I hope someone can help me with this problem.

Thanks and kind regards,
David