On Fri, 2 Nov 2018 08:39:28 +0100
Kalin KOZHUHAROV <me.kalin@gmail.com> wrote:

> On Fri, Nov 2, 2018 at 8:26 AM Laszlo KERTESZ
> <laszlo.kertesz@gmail.com> wrote:
> > The current FDroid build (version 0.0.20181031) is broken. The Gui
> > starts but it states "Unknown userspace Go version" and the tunnel
> > activation action results in an error. 
> Hmm... just installed (1st time) and started it, seems fine (haven't
> configured it yet).
> What is your configuration?
> 
> Here: stock (no root) Android-8.1.0 (3.18.71-perf-gd0e0d1a kernel) on
> XT1905 phone.
> 
> Kalin.

I got the problem too after the WireGuard update. Error is: 
 No implementation found for java.lang.String
 com.wireguard.android.backend.GoBackend.wgVersion()

LineageOS 15.1-20181030 (Android 8.1.0), without Google Play Services,
Device Xiaomi Mi A1.

Full log attached.