Asus RT-AC56U Android Client gives: Error message: X509:parse_perm:error in cert::error:0480006C:PEM routines::no start

[Chinquapin]

I'm new to setting up a VPN server. My router natively supports OpenVPN in either server or client mode. I configured it as a server for use w Android clients. The OpenVPN Android client imports the server-generated .ovpn file w/o complaint, but trying to connect gives:

"Error message: X509arse_perm:error in cert::error:0480006CEM routines::no start"

I'm clueless as to what this means or what to do about it, or even where to start. Can anyone point me in the right direction to being able to understand this, please? Many thanks.