If I change to "Index Properties Only" I thought I would loose the access to TAGs?
That option makes the indexer to only gather metadata properties (title, subject, author, tags, etc.), using a property handler, such as the one in PDF-ShellTools. The other option uses the property handler to index metadata properties, and an IFilter to index the text content. In older Windows versions the IFilter was used to index metadata too.
Here is where Adobe iFilter comes from:
That links to the 64-bit version of the IFilter. Newest versions of Acrobat and Acrobat Reader include a 32-bit IFilter, so you only need to install that one if you have a 64-bit Windows.
Probably your installed IFilter was the older version, that Adobe provided as standalone.
2. Then I changed the FILE TYPE indexing Method to "file properties only". That AUTOmatically changed the Description from "PDF Filter" to "File Properties Filter".
The second step appears not to be necessary. I went back and tried both options (file properties only - and- file properties and contents). They both seem to work ok.
So the culprit appears to be an iFilter that got installed somehow. Probably the "built-in" PDF-iFilter that comes inside Adobe Reader.
I think this works now. Whew !
Excellent! Probably an older version of the PDF IFilter was the real culprit. My suggestion to change to "file properties only" was to test that possibility, as the IFilter included in the new Acrobat and Acrobat Reader versions works fine.
Indexing the content may be important or not. It depends on your PDFs management needs, but if metadata properties are enough, disabling the content indexation makes the background indexer process almost imperceptible. Not so when large PDFs content is being indexed.