Nestlé had to prove that KitKat was recognizable enough to be trademarked in all EU member states. EU courts said that there was insufficient evidence to prove that in Belgium, Ireland, Greece, and Portugal.
From the KitKat spat to trainer wars: What happens when
Nestlé's fingers burnt in Kit Kat battle
KitKat loses court battle over shape of its chocolate bars
Kit Kat 2 Finger Mint 8 Pack Dark Chocolate : Grocery
No break for Swiss giant Nestle in Kit Kat trademark war
Nestle loses battle to give 4 finger KitKat protected trademark
No break for KitKat in Europe as trademark request rejected
Nestle loses EU Kit Kat TM battle with Mondelez - Just Food
KitKat loses 16-year-old case to trademark its 4-fingered wafer bar