Merge pull request #196874 from dominicbetts/central-edge-version-note

IoT Central - IoT Edge version warning

Author: PRMerger3

articles/iot-central/core/concepts-telemetry-properties-commands.md

@@ -51,6 +51,9 @@ IoT Central lets you view the raw data that a device sends to an application. Th
 
 If the telemetry is defined in a component, add a custom message property called `$.sub` with the name of the component as defined in the device model. To learn more, see [Tutorial: Create and connect a client application to your Azure IoT Central application](tutorial-connect-device.md).
 
+> [!IMPORTANT]
+> To display telemetry from components hosted in IoT Edge modules correctly, use [IoT Edge version 1.2.4](https://github.com/Azure/azure-iotedge/releases/tag/1.2.4) or later. If you use an earlier version, telemetry from your components in IoT Edge modules displays as *_unmodeleddata*.
+
 ### Primitive types
 
 This section shows examples of primitive telemetry types that a device streams to an IoT Central application.

articles/iot-central/core/troubleshoot-connection.md

@@ -194,10 +194,11 @@ To detect which categories your issue is in, run the most appropriate Azure CLI
 
 You may be prompted to install the `uamqp` library the first time you run a `validate` command.
 
-The two common types of issue that cause device data to not appear in IoT Central are:
+The three common types of issue that cause device data to not appear in IoT Central are:
 
 - Device template to device data mismatch.
 - Data is invalid JSON.
+- Old versions of IoT Edge cause telemetry from components to display incorrectly as unmodeled data.
 
 ### Device template to device data mismatch
 
@@ -243,6 +244,10 @@ If there are no errors reported, but a value isn't appearing, then it's probably
 
 You can't use the validate commands or the **Raw data** view in the UI to detect if the device is sending malformed JSON.
 
+### IoT Edge version
+
+To display telemetry from components hosted in IoT Edge modules correctly, use [IoT Edge version 1.2.4](https://github.com/Azure/azure-iotedge/releases/tag/1.2.4) or later. If you use an earlier version, telemetry from components in IoT Edge modules displays as *_unmodeleddata*.
+
 ## Next steps
 
 If you need more help, you can contact the Azure experts on the [Microsoft Q&A and Stack Overflow forums](https://azure.microsoft.com/support/community/). Alternatively, you can file an [Azure support ticket](https://portal.azure.com/#create/Microsoft.Support).