I am seriously sick because all of sudden variations pages have stopped working. I have no clue on how can I fix it :( See below:
In your case, as you said, the size of your Content Database is not large (I assume you might also be not on production farm) therefore I would recommend you restoring the Content Database from any other server or backup source (Production) again.
There is a built-in tool
In your case that's the -fix that will be helpful as it will allow you to correct
You also have the -scan switch to first get an overview of what could be broken.
Hope it helped.
Can you look in the list:-
and ensure the values look correct?
You should have the following fields present:-
Heirarchy Is Created