Script hangs while creating bridge - somewhere between line 1743 and 1754

[artemislena]

The title basically says it already. I'm using it on a NanoPi R1, with the default eth0 and wlan0 interfaces from the config file. It hangs between saying Create a bridge interface... and actually doing this; entering ip link or ip a in a separate SSH session doesn't show any interface apart from the default ones.