WireGuard on macOS stopped working after 1.0.10 update

[Glenn Schmidt]

After I installed the new WireGuard update from the Mac app store, I can’t connect my tunnel. The message in the UI is "Unable to apply network settings to tunnel object."

I’m using macOS 10.15.7. I've tried rebooting, removing and re-importing tunnel configs, deleting and re-installing the WireGuard app.

Here’s a dump of possibly-relevant warnings in Console.app during a connection attempt:

error	10:47:01.801958+1100	WireGuardNetworkExtension	Bootstrapping; external subsystem UIKit_PKSubsystem refused setup
error	10:47:01.837971+1100	nehelper	-[NWPrivilegedHelper startXPCListener]_block_invoke client pid 111 does not have any known entitlement
error	10:47:01.838068+1100	configd	networkd_privileged_check_interface_settings_block_invoke received XPC_ERROR_CONNECTION_INVALID
error	10:47:06.947361+1100	WireGuardNetworkExtension	Starting tunnel failed with setTunnelNetworkSettings timing out
error	10:47:06.955318+1100	nesessionmanager	address is loopback
error	10:47:06.959919+1100	nesessionmanager	address is loopback
error	10:47:11.985280+1100	WireGuardNetworkExtension	SIOCGIFMTU failed: Device not configured
error	10:47:11.985358+1100	WireGuardNetworkExtension	NEVirtualInterfaceAdjustReadBufferSize: interface_get_mtu failed (6), defaulting to max mtu
error	10:47:11.988228+1100	neagent	[u E64DEC42-DC15-401F-8590-DAFE723FB670:m (null)] [<private>(<private>)] Connection to plugin interrupted while in use.
error	10:47:11.989727+1100	neagent	[u E64DEC42-DC15-401F-8590-DAFE723FB670:m (null)] [<private>(<private>)] Connection to plugin invalidated while in use.