I had a bad surprise leaving the conference yesterday. My license plates were missing, replaced with a letter informing me the car was de-registered and I must contact the vehicle office. I could not imagine worse timing for this, with international guests to pick up from the hotel in the morning and the next two days full with conference activities. It necessitated making alternate travel plans for my guests and missing the first session of the conference to straighten things out at the vehicle office.
It turns out that my insurance company sent the wrong person-number to the registry last year when I bought the car, so the government thought I'd been driving without insurance for a year. They sent me a letter last year, but the folk-registry had the wrong address (a street number of 1 instead of 21) and so we never got the notice. Two separate typographical errors combined to cause trouble.
It didn't take long to straighten out, but it was a bad surprise at the very worst time. Sometimes even when you do everything right, things still go wrong!