Can´t do crush/marry mission

[Johnniecash]

So I got a new mission telling me the cute story about my faction heir falling in love with his fathers sister and I should get them together as soon as possible. Ignoring the morale aspect of this , I selected the princess and took her to the general.

However, when I rightklick to engage them I get a message telling there are no potential generals in the army and with that no marry button. So now I can´t succeed with the mission. Is this a bug or am I doing something wrong?
I´ve doublechecked it´s the right two characters and are sure how to create a marriage so I really don´t know what to do now. Please help me!

[pwijnands]

Just marry the princess of to someone else and the mission will expire.

I hate certain missions in this game. I once got asked to annex a settlement from a longtime enemy that only had two settlements.

[Summitz]

Yes, this happens, you have to be careful with this mission, when this mission pops up, the prince in the question or the princess in the question is not married, but then you see the suitability stuff pop up in the screen all the time, telling you have you have a suitable prince/princess to be married into your royal family, MAKE sure that you DONT. Check the name of the prince and princess to be married, and then MAKE SURE, that they are only married to the person the misson states, otherwise there is no other way to complete the mission.