Denali 16.3.8

[hkubat]

After loading 16.3.8 on my ws-3850-24p I am unable to enter the command :

no vstack

...is it not supported?

[balaji.bandi]

Can you check with - show vstack config ( either it is enabled or disabled)

[Leo Laohoo]

Look at the release date of the IOS.
Any IOS/IOS-XE released after July 2018 will no longer support "vstack" command.