In which cases AES doesn't need IV? I was trying to decrypt a text encrypted with AES and ECB mode.
I did try several keys and IV. I solved it by ignoring IV. (The IV was given, but it was maybe a distraction)
My question is in which cases IV is needed and in which is not?
A quick list from Wikipedia;


ECB : doesn't use IV and don't use ECB which is insecure, see the penguin from Wikipedia.
CBC : uses IV
PCB : uses IV
CFB : uses IV
CTR : uses IV
OFB : uses IV
GCM : uses IV
CCM : uses IV
....


In short, all secure modes need an IV. To achieve semantical security the Probabilistic encryption is required.