Knowledge Base

Problem

Observer XT fails to launch and displays an error such as 'hardware key not found' or 'Error when starting the aksfridge service… Status Code: 48 5 951 2', indicating that the Sentinel HASP license driver is missing, outdated, or blocked.

Details

Affects installations using a physical USB dongle for licensing. Can occur after a fresh installation on a new machine, after an OS update, or when IT security policies block driver installation (common on hospital or university-managed computers). Seen in Observer XT 14.2 and other versions using hardware-based licensing.

Solution

1. Confirm you are using a USB dongle (hardware key) rather than a software-based activation code.
2. Uninstall any existing HASP or Sentinel driver from the machine via Control Panel > Programs.
3. Download and install the **HASP 8.13 driver** (link provided by Noldus Support upon request, or contact [email protected]).
4. Reconnect the USB dongle after the driver installs, then launch Observer XT.
5. If IT security policies block the driver, escalate to your IT department and share the driver name (Sentinel HASP/LDK) so they can allow it.
6. If the issue persists on a managed/hospital computer, contact Noldus Support to discuss switching to a software-based (SBLK) activation code, which does not require the HASP driver.