Blueprint Sentry Print - Object Reference not Set

  • Published on Oct 18, 2025
  • 1 minute(s) read
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Issue

When a user swipes a badge on printer to login, the screen shows a prompt for card registration even though the user has previously registered, and at the same time, Blueprint Event Viewer is showing “Object reference not set to an instance of an object” 

 

Analysis

Open Blueprint Taskmaster.log and see if the terminal is missing.

[2025/07/02 15:51:33 P1994 D001 T059 d TaskMaster] [BniService.ExecuteAuthenticationScriptInternal] Executing authentication script for terminal '' and user session id '', with type '-1'.

For reference, here is snippet of Taskmaster log from my server to show what it suppose to look like:

[2025/07/07 09:54:20 P3B8 D001 T01D d TaskMaster] [BniService.ExecuteAuthenticationScriptInternal] Executing authentication script for terminal 'MyTerminal' and user session id '798b92e0-d3da-40a8-9001-dc0cd550c507', with type '9e0a640b-88f6-4ee5-9457-d512fdb97727, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.

Solution

  1. Un-secure the printer.
  2. Open Blueprint Administrator on Analyst server and go to Device Management > Terminals and verify that the printer’s terminal no longer exists in the Terminals view.  If it exists, manually delete it. 
  3. Re-secure printer.

If the issue persists (Object reference not set to an instance of an object is still showing in Blueprint Event Viewer), 

  1. In Blueprint Administrator, go to Servers > Servers, click the associated Collector on the right view.
  2. Click “Clear Replicated Data” on the top left menu, and wait until “Replicated data cleared successfully for all selected servers” appears.