If you activate the paranoid mode of class WebServer since version 3.0, it rejects all connections because of the following bug in constructor of private class AddressMatcher:
line ~89 of head revision of class WebServer:
pattern[i] = Integer.parseInt(next);
should be rolled back to:
pattern[i] = (byte) Integer.parseInt(next);
as in version 2.0
Without the casting, the IP pattern is not correctly recorded and therefore all supposed accepted IPs are denied...

It's a major bug of v3.0 to me.