FarmerTeresa (GB1)

I've tried at least 10 times to buy an olive. I have 159 olives and I need 160 to make olive oil. I don't particularly want to wait hours for my next crop to ripen so I want to buy one single olive for 900 dollars. The option is there, the button isn't greyed out, I have the dollars, but every time I click on buy, nothing happens. Is there a reason for this?