Hi Mario,
the link on https://www.photools.com/support/ to the knowledge Base is broken (404 page not found). It points to:
https://www.photools.com/category/imatch5/imatch-5-knowhow/
The link "DAM Knowledge Base" at the bottom of the page works, supposedly because the link target is different. Maybe some leftover from the restructuring of your Web presence?
As a workaround you will see DAM knowledge base at bottom of page (black background) or use this url:
https://www.photools.com/category/imatch5/dam-knowledge-base/
Link fixed, thanks.
(Nothing is older than a link :D)