Leak in the roof

Hi all,
Came home last night to water in the bathroom and noticed dripping coming from the join of the outside wall and the ceiling. Went up into the loft to investigate and found that there was a slit in the loft felt and that water was coming in through it and down onto the insultaion and through the boards. I put my finger through the felt and can see daylight through the tiles so I'm assuming they've either slipped or cracked? Once the tiles have been fixed / moved back into place should this resolve my problem or do I need to replcae/fix the felt too?

Its going to be pretty hard to say what it is without a photo but yes there is a problem with the tiling somewhere.

Could be something as simple as a broken/slipped tile or it could be something a little more complicated such as a valley or flashing problem.

The felting should be fixed at the same time as the repair is made.

fix the tile and u will be alright