How to extract HomeAssistant configuration form VDI image (OracleVM)

I had HomeAssistant as VM under OracleVM in Widnows. I used it to learn and test.

One day I did HA update and after that it just refused to boot.

I created new VM and had to go from scratch as I did not make any backup. Well, I was testing, it did not even crossed my mind to do backups.

So all my examples of configuration and scripts are locked in that vdi file.

I would like to restore them.

According to few sources (that may be outdated) I found out that vdi is just an archive that contains img file so it should be easily accessible. But in my case I can view content of vdi archive and it indeed is img file, but I cannot extract it as 7zip complaints about unknown compression.

Has anyone managed to hack this?

Are you sure there is no backup as HA by default creates a backup before applying an update. Unless you are not using HAOS

There are backups but they were all at the same VM machine so locked inside VDI image.