Fix the cause of a sensor error message

  • Release version: Australia
  • Updated May 28, 2026
  • 1 minute to read

    • To fix a Discovery sensor error message, you must fix the JavaScript file containing the code that generated the error.

    Before you begin

    Verify the following:Role required: admin

    About this task

    Use the sensor name and stack trace you identified in Find the cause of a sensor error message to locate the failing code. The stack trace provides the line number and function name where the error occurred.

    Note:
    The exact fix depends on the specific sensor and payload. This topic describes where and how to fix the error, not specific code changes. For errors with a refined code, you can view the root cause and remediation steps directly on the page.

    Procedure

    1. Navigate to the Discovery Definition module where the error occurred.

      For example, navigate to Discovery Definition > Script Includes.

    2. Search for the sensor name in the Name field.
    3. Select the link to open the record.
    4. Locate the failing function or line using the stack trace, then correct the JavaScript.
      For example, if the error indicates it "Cannot read property X of undefined", add a defensive check around the payload fields.
    5. Select Update.

    What to do next

    Rerun Discovery to verify the sensor no longer generates the error. If the error persists after applying the fix, contact ServiceNow Support and provide the full stack trace, the sensor name, and a description of the changes you made.