This KB article addresses the process of upgrading multiple devices to version 21.2R3-S7.7 from the Mist Cloud and outlines the necessary steps to follow the required upgrade path. Due to the unavailability of intermediate hops on the Mist Cloud, it is crucial to ensure a seamless upgrade process while adhering to the recommended path.
Currently, upgrades to the SRX from the Mist Cloud are only supported on version 21.2R3-S7.7 and subsequent releases. If you do not meet these requirements, we recommend opting for a manual upgrade to the SRX device to reach the supported Junos OS version or any other target version. You can reference the provided documentation to facilitate the manual upgrade process effectively.