Janome does not host the full installer for public download because it requires a paid license. However, if you already own the dongle:
If you don't already have the USB dongle, you cannot "just download" the software. You must buy it. Prices range from $199 to $299 USD. janome digitizer jr software download
Problem: "The setup files are corrupted." Janome does not host the full installer for
Problem: "No compatible USB key found."
Problem: The software crashes when importing a JPG. Problem: "No compatible USB key found