In the history of this country, has a candidate ever been disqualified after the fact and the position goes to the runner up? I don't think that's a thing that has ever happened.
Sorta happened with a PA State Senate race in Philly back in 1994 (which actually shifted control), but that was moreso because of voter fraud than candidate ineligibility
NYT linkAre there any rules in Virginia about living in the district x years from election day or taking office? I think sometimes because of redistricting, those rules get thrown out in court at least for the first race after a redistricting.