Animation Charts Pack not compatible with TBS8.1?


I downloaded the Animation Charts Pack 1, but I cannot load any file of this pack into Toonboom Studio.
I get an error saying:

File not compatible. Please download or Update File Converter.

What is the File Converter, and if there is one, where can I find that?

There are downloadable PDF instructions of the download page for these charts.
Explain at which point in the install instructions you are getting this message.

Did you download the charts for the correct O.S.? There are separate ones
for Mac and Windows.