uploading documents for download
The path that you have entered for the file is pointing to a location on your computer.
If you hover your mouse over the link, you will see that it is pointing to a folder on D:/.
You need to update the path of the link to point to the correct location.
I suggest editing the Tech-Dry Masonry page, and at the bottom of the WYSIWYG editor, check the box labelled 'View HTML Source'.
Find the text of the link by pressing CTRL+f to bring up the find function in your browser, and type in the text of the URL (Tech-Dry Masonry Specifications).
Then update the href attribute of the link to point to the correct path as you have in the cases of the CSIRO and ABSAC links.