On beta, after a cache purge in bits, all static assets respond with 403 forbidden, that is due to the files being missing on the beta mediawiki servers.
This is due to a broken link:
ls -la /usr/local/apache/common/docroot/bits/static-master/skins
lrwxrwxrwx 1 mwdeploy mwdeploy 28 Sep 3 23:37 /usr/local/apache/common/docroot/bits/static-master/skins -> ../../../../php-master/skins
which points to the void.
When fixed, please un-cache the bits varnish:
varnisadm ban req.url ~ /
Version: unspecified
Severity: normal