Ah. I was always good about backups, but I never tested them. I used Timeshift for backups, and when I needed to recover a backup whoops! No user data. I fixed it to backup user data, and whoops! Still no user data.
Another time I used a proper backup client, but when I went to restore it it overwrote itself and so it failed and I lost the backup. Always test your backups.
Good to know! What would you like me to call the section for draw.io, since it is still great software?