As I had just started opening the box and it glowed yellow/orange, indicating there was a legendary, supermechs froze and after waiting a couple minutes it was still frozen. So, I refreshed the page and…no legendary in my inventory. When I entered the unicorn level on normal again it was a fresh level.
Supermechs froze while opening the chest from unicorn level and I didn't get items (one of which was a legendary) from the chest
Is it a red glow? Check your Special Items tab.
When its a red color,its the Unicron horn (yes that is the name) You’ll get the horn,and two other items,Ranging from Common to epic