"dash dash/sh boolean false" on install - Debian 11

Hello,
I installed Debian 11 on Workstation Pro 16 and encountered the following error during ISPconfig 3 installation. I couldn't find much on the internet for a solution to this. Can you help with this?

Code:

root@hero:~# wget -O - https://get.ispconfig.org | sh -s -- --use-nginx --no-dns --no-roundcube --roundcube --no-quota --no-mailman --no-mail --use-ftp-ports=40110-40210 --unattended-upgrades
--2021-12-23 22:38:07--  https://get.ispconfig.org/
Resolving get.ispconfig.org (get.ispconfig.org)... 104.26.10.246, 104.26.11.246, 172.67.75.112, ...
Connecting to get.ispconfig.org (get.ispconfig.org)|104.26.10.246|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2004 (2.0K) [application/octet-stream]
Saving to: ‘STDOUT’

-                                                        100%[===============================================================================================================================>]   1.96K  --.-KB/s    in 0s

2021-12-23 22:38:08 (6.37 MB/s) - written to stdout [2004/2004]

WARNING! This script will reconfigure your complete server!
It should be run on a freshly installed server and all current configuration that you have done will most likely be lost!
Type 'yes' if you really want to continue: yes
[INFO] Starting perfect server setup for Debian GNU/Linux 11 (bullseye)
[INFO] Checking hostname.
[INFO] Enabling contrib and non-free repositories.
[INFO] Updating packages
[INFO] Updated packages
[INFO] Installing packages ssh, openssh-server, nano, vim-nox, lsb-release, apt-transport-https, ca-certificates, wget, git, gnupg, software-properties-common, ntp
[INFO] Installed packages ssh, openssh-server, nano, vim-nox, lsb-release, apt-transport-https, ca-certificates, wget, git, gnupg, software-properties-common, ntp
[INFO] Activating sury php repository.
[INFO] Activating GoAccess repository.
[INFO] Updating packages (after enabling 3rd party repos).
[INFO] Updated packages
[INFO] Default shell is currently dash.
[INFO] Setting bash as default shell.
[ERROR] Exception occured: ISPConfigOSException -> Command echo "dash dash/sh boolean false" | debconf-set-selections && DEBIAN_FRONTEND=noninteractive dpkg-reconfigure dash 2>&1 failed. (/ispconfig.ai.php:15)
root@hero:~#

Thank you!

 

What @Jesse Norell wrote. In addition:

So debian is installed on a WMWare virtual host? How was Debian installed?
Did you pay attention to the ISPConfig auto installer preconditions:

 

I was getting the error yesterday, but today it installed without any problem. There are currently no issues. Thank you for your interest.

Why are you so surprised by this?
I created a new virtual machine on Workstation Pro and installed Debian 11. Then I installed the ISPconfig software.
What is unusual about it?

 

I am not surprised.

I do not know. Why do you bring up this unusual aspect? I run all my ISPConfig setups on virtual host. Some users on this forum have reported problems on cloud servers of some providers, where the OS is not a stock version but modified by the provider maybe leaving some parts out and causing problems when ISPConfig is installed. So it is useful to know on what kind of system ISPConfig is trying to install itself.

 

Just in case someone has the same problems with the installer. I just found out that it has something to do with su! When i login with su, i have this error, but if login with su - or su - root, the error seems to be gone.

https://serverfault.com/questions/976289/bash-dpkg-reconfigure-command-not-found

 

There is also enough if one forgets to add the - after the su command, using su instead of su - will cause the error.

 

That is what @till wrote and what the autoinstaller manual and ISPConfig Perfect Server guides say. Why is this thread attracting re-inventors of using su - ?