Runeword doesn't work

Hi

I have created season 5 ladder character. When i reached 16 lvl i wanted to make “Stealth” runeword on chest with 2 slots but it didn’t work. Now i have chest with just Tal Eth runes. I don’t want to play further if runewords doesn’t work at all.

BR
Cromer

Did you use a grey base ?

Runewords don’t work in blue, yellow, green or gold items.