Full error message:
Notice: Undefined index: width in /srv/mediawiki/php-1.28.0-wmf.20/includes/Linker.php on line 750
Notice: Undefined index: width in /srv/mediawiki/php-1.28.0-wmf.20/includes/Linker.php on line 752
it continues until this very day:
2016-10-23T01:17:36
Notice: Undefined index: width in /srv/mediawiki/php-1.28.0-wmf.22/includes/Linker.php on line 750