I have the same issue

[fethi@c_corax ~]$ opera --debug

(opera:1802): libnotify-WARNING **: Failed to connect to proxy
** Message: Remote error from secret service: org.freedesktop.Secret.Error.IsLocked: Cannot create an item in a locked collection
** Message: Remote error from secret service: org.freedesktop.Secret.Error.IsLocked: Cannot create an item in a locked collection
[fethi@c_corax ~]$ [1223/195325:ERROR:native_backend_gnome_x.cc(523)] Keyring find failed: 
[1223/195348:ERROR:object_proxy.cc(583)] Failed to call method: org.freedesktop.NetworkManager.GetDevices: object_path= /org/freedesktop/NetworkManager: org.freedesktop.systemd1.NoSuchUnit: Unit dbus-org.freedesktop.NetworkManager.service not found.

using Opera 42.0 on 64bit XFCE/archlinux