Problems with apt-get/apt when installing or removing packages.

[Moltke]

No bro! I wasn't doing that. By the way, what do you mean with modify/remaster Linux Lite .iso file?

I thought you were trying to do that since you removed/installed whisker-menu which is already installed by default, that and the fact you were using root to do such basic things. Remaster means modify the original .iso file; remove/install pkgs, make your own customizations, so it's a bit different.

What do you mean with wrong path? I used sudo -i for root. I'm not an expert! Is there any problem when I'm running everything in root?

Usually once should not use/become root unless strictly necessary, i.e. modify certain system files the regular user can't. It's a bit risky since you could damage your system beyond repair; root can do anything and that includes break things.