Hi.

Since I upgraded the SilverStripe site to the newest version, I am not able to access the admin interface through a secure connection anymore. All I get is a blank page. Here is what happens:

1. I open the URL https://mysite/admin.
2. An HTTP basic-auth dialog pops up.
3. I enter my credentials.
4. My browser is redirected to https://mysite/Security/login, the page asks me for my credentials again.
5. I enter my credentials.
6. My browser is redirected to https://mysite/admin, but I see a blank page.
7. If I then manually open the URL https://mysite/Security/login, it reads "You're logged in as <me>".

If I do the same with the non-secured connection, i.e. http://mysite/admin, everything works as expected: I only see one authentication dialog and can then access the admin interface. SSL itself works fine, as I can view any regular page via HTTPS, e.g. https://mysite/some-page/.

Additionally, when I open the URL https://mysite/admin, the Apache error logs contain the following entries:

This error already occured to me when I tried to upgrade from 2.3.3 to 2.3.4, so I rolled back to 2.3.3 and didn't invest to much time into troubleshooting.

Any suggestions?

-Christian