- Played adventure mode in last season so why is it locked in he new one?
- Cannot play adventure more in the new season, but I played it on the previous
To unlock the Adventure Mode for the first time you must own Reaper of Souls and complete the Act V until you earn achievement "Don't Fear the Reaper".
Softcore and Hardcore go separately: unlocking Adventure Mode in Softcore does not unlock it in Hardcore, and vice-versa.
If you unlock Adventure Mode with a non-seasonal character, this will unlock Adventure Mode for all future seasons. If you only play seasonal characters you will need to unlock Adventure Mode every season.