Eligible player cannot be used for the Backline Booster -Juan Iglesias Chain Evo

*snip* I have the same problem with the Backline Booster development. When I put Juan Iglesias, I cannot put him, and when I put another player, I can put any other player. I hope to solve it as soon as possible before the development time ends.

(CM: Edited to remove additional language. Please only post in the language of the board per rule.)