This is a bit of a complex set-up so bear with me.
To replicate this issue build a Hideout so it completes overnight (after 00:00 server time). I am not sure if you need to build more than one level of Hideout. Leave the Ikariam tab open overnight. In the morning the Mayor icon will be lit. Click that and read the notification about the Hideout. Click the link and go to the Hideout. Overlaid will be the Daily Bonus window, giving wine to a particular town and counting towards your bonus cargo ships. Get past that and try to recruit your new spy. Notice that despite the slider bar being on the right the 'Recruit' button is still greyed out.
To recruit the new spy, simply close the Hideout window and go back in and you'll be able to recruit as normal.
