IIS AppPool user permissions not working
<p>I'm moving a PHP app from IIS7 to IIS8.5 on Win2012 R2.  The app runs in its own application pool (MyPortal) and needs write permission on a sub-folder to create PDFs.  So I assign Modify or Full Control permissions to <strong>IIS AppPool\MyPortal</strong> on the local machine, however the app is still unable to write to the folder.  The only way I have found to allow it to do so is by giving Modify access to the local USERS group, which I'd rather not do (although I have no choice ATM).</p>

<p>The php-cgi.exe process is running under the MyPortal identity, but somehow isn't picking up the permissions I have assigned to the MyPortal user on the folder.  The PHP process is doing a simple fopen command <code>$file = fopen($tmp_filename,"w");</code>.</p>

<p>I saw this similar post <a href="https://serverfault.com/questions/570033/iis-iusrs-and-defaultapppool-permissions-do-not-work">https://serverfault.com/questions/570033/iis-iusrs-and-defaultapppool-permissions-do-not-work</a> which suggested it may be a permissions caching issue, solved by a reboot, but that's not worked in this instance.</p>

<p>Any suggestions as to what's wrong?</p>