I tried putting them in the relevant folders in the Share section, but they didn't show up. The brushes in question are here: https://colorathis.wordpress.com/2013/0 ... rushes-v1/

I'm using the 3.3.3 .appimage version on Linux but the principle should be the same. All I can do is tell you what I've done and seen:

I could Import the presets with Settings -> Manage Resources -> Import Presets but the brushes would not import with Import Brushes. The presets then appeared in the Brush Presets docker with a large 'X' symbol on them to indicate their brushes were not present.

The brushes are .gih files which you can actually open with krita to see the layers containing about twenty or so different brush patterns.

After I copied these .gih files to the brushes folder (the same one that contains all the usual .gbr brush files) and then restarted krita, they all worked. The Brush Presets docker icons no longer had an 'X' on them and the brushes worked fine.

Do you only use the 4.0 Portable version on your PC? Can you try the installed or .appimage 3.3.3 version? Do you see the 'usual' brushes and presets in the brushes and paintoppresets folders? Have you previously been able to Import or otherwise install other brushes and brush presets?