PDF indexer returns 404 error on found URL

I've purchased the PDF Indexer package to allow registered users of our website to search the newsletter PDFs. I've installed the component in version 5.4.2 of Joomla; configured the component; indexed the files and enabled the plug-in.
The search works as expected (first image) but the link to the file returns a 404 error (second image)
Is there an additional configuration value that I need to set?
 

Hi Dick,
Could you please submit ticket into category: Edocman and provide your site url and super admin account for checking the problem?
Thanks
Dam

I have the same problem. Everything worked correctly after installing PDF Indexer 4.0 in December. I don't know when it stopped working. When I noticed the problem today, I updated the Indexer to 5.0 and Joomla to 5.4.3. It still doesn't work.
houben.eu/

Hi Arnold,
Please submit ticket on category: Edocman and provide your site url and super admin account. I will check the issue for you.
Thanks
Dam