Cannot install Virtualmin in a LXC

[voarsh]

I've tried to install Virtualmin inside a Ubuntu LXC.
I keep getting:

Installing Virtualmin and plugins [ OK! ]
3 Dec 03:34:43 ntpdate[12665]: Can't adjust the time of day: Operation not permitted
Installing updates to Virtualmin-related packages [ OK! ]


[9/23] Configuring Net ▒▒▒▒▒▒▒Error: Unable to open /etc/network/interfaces
█▒▒▒▒▒▒Error
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Unable to open /etc/network/interfaces
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▣▣▣ Cleaning up

[WARNING] The following errors occurred during installation:

◉ Postinstall configuration returned an error.


Note, it is a privilege LXC.

Just an FYI: it works just fine on a VM. Although I wanted a LXC for lower resource usage.