error when upgrading from 18.04 to 20.04 package mdadm 4.1-5ubuntu1.2 failed to install/upgrade: installed mdadm package post-installation script subprocess returned error exit status 128

I did the release upgrade with the "sudo do-release-upgrade" command.
I'm running a server with two HDD in raid 1 configured with mdadm.
Tell me if you need other information about my hardware or configuration.

After restarting the server, I still had problems with the mdadm package, apt upgrade failed each time because of mdadm. I solved my problem by removing and reinstalling mdadm :

dpkg --force-all --remove mdadm
dpkg --force-all --purge mdadm
apt-get install -y mdadm
(I found that here : https://askubuntu.com/questions/924306/mdadm-blocks-apt-get-upgrade#1203667)

apt remove was not enough to fix the problem.

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: mdadm 4.1-5ubuntu1.2
ProcVersionSignature: Ubuntu 4.15.0-128.131-generic 4.15.18
Uname: Linux 4.15.0-128-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
CasperMD5CheckResult: skip
Date: Mon Dec 21 12:05:47 2020
DuplicateSignature:
 package:mdadm:4.1-5ubuntu1.2
 Setting up mdadm (4.1-5ubuntu1.2) ...
 dpkg: error processing package mdadm (--configure):
  installed mdadm package post-installation script subprocess returned error exit status 128
ErrorMessage: installed mdadm package post-installation script subprocess returned error exit status 128
Lsusb:
 Bus 002 Device 002: ID 174c:55aa ASMedia Technology Inc. Name: ASM1051E SATA 6Gb/s bridge, ASM1053E SATA 6Gb/s bridge, ASM1153 SATA 3Gb/s bridge, ASM1153E SATA 6Gb/s bridge
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 8087:0a2a Intel Corp.
 Bus 001 Device 002: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: AZW BT3 X
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-128-generic root=UUID=58352f9f-9ce7-4e2c-bc55-5d6494f5402d ro
Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: /usr/bin/python2.7, Python 2.7.18, python-is-python2, 2.7.17-4
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.2ubuntu0.2
SourcePackage: mdadm
Title: package mdadm 4.1-5ubuntu1.2 failed to install/upgrade: installed mdadm package post-installation script subprocess returned error exit status 128
UpgradeStatus: Upgraded to focal on 2020-12-21 (0 days ago)
dmi.bios.date: 02/14/2019
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0.08
dmi.board.asset.tag: Default string
dmi.board.name: Default string
dmi.board.vendor: Default string
dmi.board.version: Default string
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0.08:bd02/14/2019:svnAZW:pnBT3X:pvrDefaultstring:rvnDefaultstring:rnDefaultstring:rvrDefaultstring:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: Default string
dmi.product.name: BT3 X
dmi.product.version: Default string
dmi.sys.vendor: AZW
etc.blkid.tab: Error: [Errno 2] No such file or directory: '/etc/blkid.tab'