Hard Luck - S4.E18

When Odd breaks a mirror, a little bad luck follows and jinxes him everywhere, even on Lyoko. A bug in his virtual avatar spreads to Yumi and Aelita, causing annoying pauses and random devirtualization in the Desert Replika. Meanwhile, at the site of the Replika's supercomputer, X.A.N.A. materializes Kankrelats in the real world to stop Ulrich and Yumi. Despite the bug, their mission to destroy X.A.N.A.'s next Replika ends in success, this time by Ulrich, and Odd's luck returns soon afterwards.