We haven't had an update since that one in December that im aware of.
No idea why they would not open now … But before you try stuff back them up first and the .Bak file
Then your current .Bak file can be renamed to .fpm which should be the same as the last saved map.
For example
Level2,fpm
Level2.Bak
Could be worth trying that first before you go verifying etc
The only person ever to get all his work done by "Friday" was Robinson Crusoe..