Empty "owned champions"

Hi, I haven't played for some months and now all my champions are gone. It means that if I go to Collection it shows all champions with a lock symbol and if I filter by "owned champion", it shows an empty list.

When I start a trainings game, I cannot select a champion. When I am invited in a game, I see the list, pick a champion an error message occurs but when I click it away I can play. BTW, I do see the games played yesterday in the history...

Anyone who can help?

br alex