If you are using ThinOS 9.0.1136, you cannot upgrade the ThinOS firmware or install application packages after September 2021. You must disable the time server on ThinOS, change the system time to Aug 2021, and then upgrade the ThinOS firmware or install the application package. Once you have this done download ThinOS 9.0 to ThinOS 9.1.3129 Image file for Dell Wyse 3040, 5070, 5470 and 5470 All-in-One Thin Clients
Then you will be able to upgrade to ThinOS 9.1.3129 or later to ThinOS 9.1.5067 Image file for Dell Wyse 3040, 5070, 5470, and 5470 All-in-One Thin Clients