Noob questions - OpenVPN on QNAP Server & Android Client

[JonRussell]

Hi,
I configured OpenVPN on my QNAP this weekend, and opened the various firewall ports.
I had a copy of the OpenVPN client on my phone, and when I first tested it, it worked fine!
However, the client was bugging me that there is a new version available. So I made the fatal mistake of updating the Android client, and now the VPN wont connect.

I am using:
QTS v5.1.4.2596 on a QNAP TS-431KX
Android client: 3.4.0 (9755)
I do not have a custom certificate. I think OpenVPN Server is using the default QNAP certificate.
When I try to connect I get:
"Select a certificate: The profile doesn't include a client certificate. Continue connecting without a certificate or select one from the Android keychain"
I have tried both options. There isn't any keys in the Android keychain and if I select "continue" I get:
"Connection Failed: Peer certificate verification error"

It worked briefly with the same settings before I updated the client.

If I look in the .ovpn file, there *is* a
"<ca>
-----BEGIN CERTIFICATE-----"
section.

So I think I have a client certificate in the profile?

Can anyone point me at some step by step instructions how to configure this on QNAP?

I dont want to have to buy a certificate (this is just for home use) and my QNAP isnt accessible on the internet, so using LetsEncrypt is complex too.

Is it possible to get OpenVPN working without buying or changing the default QNAP certificate? Or is this a bug in the latest clients.
I get exactly the same problem / error in the Windows client too?

Help!

Thanks!

Regards,

Jon.

[JonRussell]

I think someone moved my post to the Android Client group ... I'm not sure this is an Android problem. But I'm happy to be proved wrong.
The same problem exists on the Windows client too, as mentioned in the post.
But lets see.
I hope someone can help.

Thanks.