Form results Onknown

I have used forms for registration to an event. The first are handeled but since yesterday it sais unknown. Despite that they have entered all the required details and I have the settings "Handle all submissions automatically. Create new contact if no match is found." In my other event ther´s only one registration that isn´t handled, the ones before and after is. With the same settings. I also receved feed back that the ones that are not handeled didn't get a confirmation. Please help.