Openvpn fails after upgrade to debian 10 – buster

# tail -f /var/log/openvpn.log                                                                                                                                            Thu Feb 18 17:41:47 2021 library versions: OpenSSL 1.1.1i  8 Dec 2020, LZO 2.10
Thu Feb 18 17:41:47 2021 Diffie-Hellman initialized with 2048 bit key
Thu Feb 18 17:41:47 2021 Outgoing Control Channel Authentication: Using 160 bit message hash ‘SHA1’ for HMAC authentication
Thu Feb 18 17:41:47 2021 Incoming Control Channel Authentication: Using 160 bit message hash ‘SHA1’ for HMAC authentication
Thu Feb 18 17:41:47 2021 ROUTE_GATEWAY ON_LINK IFACE=venet0 HWADDR=00:00:00:00:00:00
Thu Feb 18 17:41:47 2021 TUN/TAP device tun0 opened
Thu Feb 18 17:41:47 2021 TUN/TAP TX queue length set to 100
Thu Feb 18 17:41:47 2021 /sbin/ip link set dev tun0 up mtu 1500
Thu Feb 18 17:41:47 2021 openvpn_execve: unable to fork: Resource temporarily unavailable (errno=11)
Thu Feb 18 17:41:47 2021 Exiting due to fatal error

# systemctl edit openvpn@
add:
[Service]
LimitNPROC=infinity

# sudo systemctl daemon-reload