I can't execute an action and don't know why

[marta_night]

So here's the situation:
I purchased a blue card that as a benefit lets me buy a green card with die value of 6. I have available space for that green card, as the military requirement has been satisfied. Still, I am not capable on clicking on any green card in my tower, which is very frustrating. Any ideas if I got some rules wrong, or if it's a bug?

Here's a screenshot: https://imgur.com/a/hUrwhhG

Many thanks in advance.

[Manuel_xxx_xxx]

Maybe you missed that you have to pay additional 3 coins for the green card as someone has already placed their meeple in the green tower?
The screenshot isn't helpful. It's missing a lot of informations.

[Manuel_xxx_xxx]

So here's the situation:
I purchased a blue card that as a benefit lets me buy a green card with die value of 6. I have available space for that green card, as the military requirement has been satisfied. Still, I am not capable on clicking on any green card in my tower, which is very frustrating. Any ideas if I got some rules wrong, or if it's a bug?

Here's a screenshot: https://imgur.com/a/hUrwhhG

Many thanks in advance.

It would have been nice to get some feedback from you regarding my answer. It's kinda rude to ask others for help and to take time for your issue and then no even answering anymore.