General availability: Azure Sphere version 23.05 is delayed to 20 June, and the updated OS has been issued to Retail Eval

**Updated 12 June** The updated OS has now been issued to Retail Eval and we expect to release the OS to retail after seven days, on 20 June. **Updated 30 May** The Azure Sphere 23.05 [release, originally expected on May 24,](https://techcommunity.microsoft.com/t5/internet-of-things-blog/azure-sphere-update-23-05-is-now-available-for-evaluation/ba-p/3816525) is delayed. A compatibility risk concerning library version dependencies was found by quality assurance tests, and we will issue a new OS to fix this. We expect the new OS to go live in [retail-eval](https://learn.microsoft.com/azure-sphere/deployment/deployment-microsoft-feeds) on 5 June and we are planning to use a shorter retail-eval period of seven days. The retail evaluation period provides a period for backwards compatibility testing. During this time, customers can verify that applications and devices operate properly with a new OS before it's deployed broadly via the Retail feed. The Retail feed will continue to deliver OS version 23.02 until we publish the 23.05 update. Areas of special focus for compatibility testing with the 23.05 release should include apps and functionality utilizing: * Azure IoT Hub * wolfSSL API calls (such as custom TLS Client or Server) * TLS connections * UART For more information on Azure Sphere OS feeds and setting up an evaluation device group, see [Azure Sphere OS feeds](https://learn.microsoft.com/azure-sphere/deployment/deployment-microsoft-feeds) and [Set up devices for OS evaluation](https://learn.microsoft.com/azure-sphere/deployment/set-up-evaluation-device-group). For self-help inquiries or technical support, review the [Azure Sphere support options](https://learn.microsoft.com/azure-sphere/resources/support). * Operating System * SDK and Tools