The best advice I can give you is go to every available hotspot/object in the game and right-click on it. In a few situations you have to right-click a hotspot/object to progress. This also lets the in-game time move forward. After that try to talk to all available characters again. A right-click might also trigger a new topic with a certain person.
For example, at the attic fireplace you will miss the piecing together of a torn photo if you don't right-click. It is probably something like this that is holding you up.