In February 2018 a 90 Million euro win was won in the town of Loimaa in Finland. None of the 16,000 residents of Loimaa has yet to claim the win a month later. If the winners do not make them selves heard within a year, the prize will be lost. The unclaimed win does not affect any ongoing Eurojackpot games.
The European wide EuroJackpot lottery has prizes ranging from 10-90 Million Euro. Countries participating in the lottery are: Croatia, Czech Republic, Denmark, Estonia, Finland, Germany, Hungary, Iceland, Italy, Latvia, Lithuania, the Netherlands, Norway, Slovakia, Slovenia, Spain, Sweden and Poland.
So far the maximum wins of 90 M€ has been won by players in the Czech Republic, Finland and Germany. Currently it is speculated that the winning coupon for the massive win is lost, and it has even spurred some locals to post a humorous ad in the local Loimaa region newspaper:
Lost: game coupon; Eurojackpot for round 6/18. Fell on the Prisma parking lot on 8.2-18. Finders fee, if the found coupon is the one having significant sentimental value.