Running 32-bit programs on 21.04

I am new to Ubuntu and might have made a big mistake, just installed Ubuntu 21.04 on an old PC and trying to run a 32 bit program on it. Looking it up it appears I have to run the following to make it compatable with a 64 bit operating system. dpkg --add-architecture i386 apt install lib32z1

On running “dpkg --add-architecture i386” I get

dpkg: error: configuration error: /etc/dpkg/dpkg.cfg.d/multiarch:1: unknown option 'foreign-architecture'

Looked at the offending file “foreign-architecture i386”. On running “apt install lib.32z1”

root@g1gxb-ubuntu:/home/g1gxb# apt install lib32z1
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following package was automatically installed and is no longer required:
  libllvm11
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
  libc6-i386
The following NEW packages will be installed
  lib32z1 libc6-i386
0 to upgrade, 2 to newly install, 0 to remove and 0 not to upgrade.
Need to get 0 B/2,689 kB of archives.
After this operation, 13.7 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
dpkg: error: configuration error: /etc/dpkg/dpkg.cfg.d/multiarch:1: unknown 
option 'foreign-architecture'
E: Sub-process /usr/bin/dpkg returned an error code (2)

Where am I going wrong?

Solution 1:

Problem solved. Had to delete two files in the /etc/dpkg/dpkg.cfg.d, Multiarch and pkg-config-hook-config and then it all worked