Hi Vikram,
Thank you so much for taking the time to fill this bug report.
This looks to me like a debconf error when part of a downloaded package
can't succeed for some reason, I know the error is a bit obscure but it
has happened before as noted by question #166815
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https://bugs.launchpad.net/bugs/1014773
Title:
package winbind 2:3.5.8~dfsg-1ubuntu2.5 failed to install/upgrade:
subprocess installed post-installation script