PHP post_max_size local value overridden by master value?
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I'm running into a strange issue when uploading large files via PHP (through Drupal, though that's not the issue).

Basically, my file uploads fail due to post_max_size limits being reached, even though the local directive is set to 96M, and the file is 25M. 

I've ensured everything else is correct, including `max_input_time`, `max_upload_filesize`, and the IIS FastCGI idle time. All these are plenty large and not the issue.

I am overriding the `post_max_size` directive through Plesk, which (I believe) stores the change in a registry value. Running phpinfo() on the domain shows the correct local and master values for all directives...96M local, 12M master.

The very strange thing is that when I change the master `post_max_size` in php.ini from 12M to 96M (and ensure the change has taken effect), **it works!** Changing the master value back to 12M immediately causes uploads to fail again.

Is this a bug in PHP, or am I doing it wrong?