I have been using my purchased copy of Fileseek for a while with no issues. Recently I noticed that it does not have PDF handler any more for some reason. I looked up some of the links you provided for installing the PDF IFILTER, but those links are bad links.

I looked around more and found this page on your site: https://www.fileseek.ca/FAQ/?Version=6.7.0.0#filehandlers, and re-installed the 64-bit FILTER. It seems to work now. I don't know how I lost it though. But anyway it seems to be OK now.