When customer try to install onbox agent in the running 24.4R1-S2.8-EVO device, NOS upgrade into 24.4R1-S2 fails, however, the device agent stuck in-progress status (Post Upgrade Full Config Push Status)

Lab reproduction: 

Issue reproduced using Junos-EVO device. When we try to install onbox agent in the running 24.4R1-S2.8-EVO device, NOS upgrade into 24.4R1-S2 fails, however, the device agent stuck in-progress status (Post Upgrade Full Config Push Status)

RCA: 

We observed an error message that the Apstra 5.1.0 device installer image for EVO is not compatible with EVO 24.4R1-S2.8-EVO.

Recovery Procedure: 

1) Cancel the NOS upgrade job for the device.

2) Undeploy the device from the blueprint.

3) Uninstall the agent (it should be a success). The device should be in the pristine configuration of the 24.4R1-S2 version in this case.

4) Delete the agent (it should be success)

5) Delete the managed device (it should be success)

6) Re-onboard the device using off-box agent, instead of on-box agent, (or manually re-install a qualified Junos-EVO to the device and cleanly re-onboard the device using on-box/off-box agent). 

Workaround: 

Customer can try using an off-box agent instead of an on-box agent if they need to address a specific EVO issue using a non-qualified version.