Blizzard has confirmed that, for now, players can’t transfer their Legion Remix Timerunners to the regular World of Warcraft timeline.
Recently, players reported that the transfer button—used to move Timerunners to the current timeline—had mysteriously disappeared from the character selection screen.
In an update to a support post yesterday, Blizzard clarified that the removal was deliberate. The change due to a recently discovered exploit.
Converting Characters From Legion Remix
The Convert Timerunner to Standard feature is currently disabled. Customer Support does not have a way to convert characters. We apologize for any inconvenience.
So far, Blizzard hasn’t said when the transfer option will return.
Source: Reddit
