504101 GatewayTimeout

This article describes the causes and solutions for 504101 GatewayTimeout errors.

Symptoms

When trying to invoke a direct method from IoT Hub to a device, the request fails with the error 504101 GatewayTimeout.

Cause

Cause 1

IoT Hub encountered an error and couldn't confirm if the direct method completed before timing out.

Cause 2

When using an earlier version of the Azure IoT C# SDK (<1.19.0), the AMQP link between the device and IoT Hub can be dropped silently because of a bug.

Solution

Solution 1

Issue a retry.

Solution 2

Upgrade to the latest version of the Azure IOT C# SDK.