OpenVPN package should be upgraded accrding to those upstream bugs: https://community.openvpn.net/openvpn/ticket/225 (main) https://community.openvpn.net/openvpn/ticket/308 (duplicate) https://community.openvpn.net/openvpn/ticket/248 (duplicate)
This problem occurs when package from Jessie is used. Problem doesn't occur when upstream latest package is used.
Regards, Mike