jslog is not supported in Service Portal client scriptsIssue When using jslog() in a client script on the Service Portal, the following error appears in the browser console: ReferenceError: jslog is not defined. This occurs because jslog() is a legacy function built specifically for the Classic (Backend/Native) UI. It relies on the JavaScript Log window found in the main ServiceNow frame, which does not exist in the Service Portal environment. As a result, jslog() is not supported in Service Portal, Service Portal Widgets, or Mobile interfaces. Release All Resolution Replace all instances of jslog() in Service Portal client scripts with a standard browser console method. Choose the method that matches the intent of the message: - console.log() — general-purpose debug output - console.info() — informational messages - console.warn() — warning conditions - console.error() — error conditions `jslog()` is a legacy function built specifically for the Classic (Backend/Native) UI and is not supported in the Service Portal, Service Portal Widgets, or Mobile interfaces. It relies on the JavaScript Log window found in the main ServiceNow frame, which does not exist in the Service Portal environment. To update a client script in Service Portal, navigate to the client script record and replace the jslog() call as shown in the following example: javascript// Before — not supported in Service Portal jslog('DEBUG', 'MyScript', 'Variable value: ' + myVar); // After — use the appropriate console method console.info('Variable value: ' + myVar); Related Links - View client scripts not running on Service Portal — troubleshooting guide KB0693343 - View supported client script types and APIs — product documentation KB1462264