if you try either to authenticate with http://wirres.net at quill.p3k.io or ownyourgram.com you get the error. (you can try it yourself, because you’re not getting to the actual authentication.)

my workaround is replacing my index.php with this file, which is empty and utf-8 encoded and produces no errors: wirres.net/hello.php

a fresh copy of php-mf2 and this code however parses my site without an error:

<?php

require_once 'Mf2/Parser.php';

// Now all the functions documented below are available, for example:
$mf = Mf2\fetch('http://wirres.net');
print_R( $mf );

(btw: bridgy now catches my instagram posts on wirres.net. turns out i had some markup problems, that are now resolved)