Acrylic WiFi makes use of its own driver to capture packets in monitor mode. Although the driver download is done in conjunction with the software download, it is not automatically installed to avoid errors on unsupported cards. We recommend that you read carefully the information about supported WiFi cards before installing it. To install it, in the drop-down menu in the upper right corner, select change mode, when selecting monitor mode for the first time, the option to install the NDIS driver will appear. After installation, you can start capturing in monitor mode.