Zen-photo version: 1.4.5, but it hasn't worked in 1.4.4 either.

Running http://my_site_here/zp-core/zp-extensions/federated_logon/Auth/OpenID_detect.php, just redirects to a blank page (http://my_site_here/zp-core/zp-extensions/federated_logon/Auth/OpenID_detect.php?test_query=a%26b).

Nothing in the debug log.

Am I doing something wrong?

Thanks,
Raymond

Did you also look into the server error log? If you get a blank page that is mostly an error Zenphoto cannot track.

I'm not sure where that is since my account is shared hosting (1and1). I asked the provider to help. Meanwhile any hint would help.

No access to the error log - 1and1 says that it's up to the application to trap and redirect errors to a file. But, I can't add an error_log directive to my local php.ini as I don't own that file.

That is really a weird answer...I only know the German 1und1 and they provide a error log via their backend if I recall right...

If the error is a fatal error in many case Zenphoto has no chance to trap the error since the scripts terminates before it can do that.