Use the everyone role to initialise the permission flags.

restapi.go

@@ -412,6 +412,13 @@ func (s *Session) UserChannelPermissions(userID, channelID string) (apermissions
 		}
 	}
 
+	for _, role := range guild.Roles {
+		if role.ID == guild.ID {
+			apermissions |= role.Permissions
+			break
+		}
+	}
+
 	for _, role := range guild.Roles {
 		for _, roleID := range member.Roles {
 			if role.ID == roleID {