Apache 2.4 producing 500 error when serving DirectoryIndex page from Shib SP protected areas

[Paul Beckett (ITCS)]

I am running RHEL6.2 , OpenSSL (built from source), Apache 2.4.3 (built from source), Shib SP dependencies - RPM's installed from yum repo, Shib SP 2.5 (built from source):
./configure --with-apxs24=/usr/local/apache/bin/apxs --enable-apache-24 --with-openssl=/usr/local/openssl

When I attempt to access a URL that is protected with  Shibboleth the , eg: https://myhost.example.org/secure/
which should automatically serve index.html (due to DirectoryIndex config), a 500 Internal server error is displayed in the browser, and the following error is logged to the Apache error log:

[mod_shib:error] [pid 8866:tid 140049100285696] [client 139.222.121.134:53006] shib_base_check_authz found no per-request structure, referer:

The page is served correctly (with no errors), if accessed as: https://myhost.example.org/secure/index.html
Pages are also served correctly via DefaultIndex in areas that are not protected by Shib SP.

Relevant Apache config:

LoadModule mod_shib  modules/mod_shib_24.so
...
DirectoryIndex index.htm index.html
...
<Location /secure >
AuthType shibboleth
ShibRequestSetting requireSession 1
Require valid-user
</Location>

Any help or advice on this would be greatly appreciated.
Thanks,
Paul
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