To resolve, you will need to update your Ironkey D300 encrypted USB drive for macOS Catalina. To update, click on the link below to
download the IKD300_Mac_Updater.app and IKD300 Mac Updater Instructions. Note: Please read the updater instructions in its
entirety prior to running the update.

Updater: https://media.kingston.com/support/downloads/IKD300_Mac_Updater.zip

For more information about the "App” not optimized or “App” needs update error message,
feel free to reference Apple’s support article. https://support.apple.com/en-us/HT208436

macOS: IKD300_Mac_Updater.app supported on macOS 10.15 Catalina.