[c-nsp] CRS1 downgrade from 4.0.1 to 3.6.2

[Per Carlson]

> I have upgraded CRS1 to 4.0.1 from 3.6.2. Upgrade worked fine and it is
> running 4.0.1. But the issue is I am not able to downgrade it back to 3.6.2
>
> I have also checked on the active and inactive files and could not locate
> upgrade package on active disk (boot disk). Does anyone has faced similar
> issue?

I think Cisco have somehow messed up the 4.0.1 upgrade PIE.

I've had an issue, not the same one as you experiences, but similar
enough on a XR12k. When trying to remove the 4.0.1 upgrade PIE it
promptly announced it would remove all other 4.0.1 PIEs as well. It
turned out this was a false alarm, they were not removed. The thing is
covered in CSCti51558.

-- 
Pelle

RFC1925, truth 11:
 Every old idea will be proposed again with a different name and
 a different presentation, regardless of whether it works.