Installation failed on virtualbox

[yellow_butterfly]

Hey everyone

I'm having a problem with Kali Linux 2020.2 installation process.
I'm trying to install Kali Linux 2020.2 on virtualbox, (the host machine is ubuntu 19.10 eoan ermine & virtualbox version is 6.1.8).
In "Select and install software" i choose KDE Plasma in eddition to the default xfce.
And everytime the installation progress fails.

I tried several times, if i choose KDE Plasma, the instaltion fails.
If i leave xfce alone, the installtion continues without any problems at all.

I just want to point out that i have a good internet connection, and Kali Linux is connected to the internet as well.
I'm not new to Linux nor Kali Linux, and i think that xfce is really cool, but i'm a big fanboy of KDE.

Please advise.

p/s: i tried to do that on NAT mode and on BRIDGE mode as well, and in both situation it fails on KDE.

[alipendier]

Same problem here on actual machine, many complaints about this on the web