Sane & Brother DCP: Invalid Argument

I’m using an old Brother DCP-135c with saned over network to scan my documents. After upgrading to newer Ubuntu versions the setup doesn’t work anymore and says invalid argument. After some tests which involved root permissions it turned out, that saned simply had no permission to access the device because the line GROUP="scanner" in the file /etc/udev/rules.d/60-brother-libsane-type1.rules was not enabled.