I had just completed a PowerShell scripted deployment of a SharePoint farm and was just performing the final checks when I noticed the following error in the crawl logs.

“The filtering process has been terminated”

This turned out that because in the PowerShell script I had specified that the SharePoint installation location should be different to the default location.  The SharePoint installation routine had not associated the correct permissions for the WSS_WPG group.

In my instance I had specified that SharePoint should be installed onto a non system disk and I had also specified different directories for indexes and logs.

To fix this I added the WSS_WPG with full control to the following directories.

%:\Program Files\Microsoft Office Servers\15.0\Data\Office Server\Applications
c:\Windows\Temp
%:\SharePoint\Index

Once the correct permissions had been applied I ran a full crawl and no longer received this error.