TeutonicCrusader said:

Cannot retire Adventurers ....why? When i click on a guardian to upgrade the Adventurers that I have don't show up to retire ,only regular Guardians. And yet my Adventurers are still there when I don't click to upgrade a Guardian

Hello Teutonic! Adventures can be upgraded just one time, and you need guardians same color to retire for being able to upgrade them.
For instance: You have a 3 star blue adventurer ... you can upgrade him to 4 stars but you will need 3 blue guardians 3 stars to do it.