Can't declare war on Yugoslavia. Need help

[unmerged(296386)]

Having problems declaring war on Yugoslavia.

Playing Germany and I'm are at war with the allies. Yugoslavia left the military alliance it had with me and I decided to punish them for this. Assembled troops at the border and tried to declare war but that option is blacked out on the diplomacy screen. Is this a bug or is there a reason for this? Fairly new to this game. Only my second time playing so still have a lot to learn.

Ps using version 1.05

 

[Gringoesteban]

It is a bug because sometimes the diplomacy screen gets greyed out for no reason. If it happens with the Soviet Union, you can declare war on Mongolia or Tanu Tubu because USSR is allied with them. But with Yugoslavia you will have to wait 2 weeks for the diplomacy option to reset. You can save and reload the game. That might help because sometimes if you wait 2 weeks the same thing happens again and the diplomacy option is greyed out all over again for another 2 weeks.

 

[unmerged(296386)]

Was almost 4 months between the breakup of the alliance and me trying to declare war (wanted to wait until I was finished with France and Britain). Tried waiting a little more and also reloading like suggested but both with no effect.

Just noticed that I'm still at war together with Yugoslavia against the Netherlands. Can this be a reason for not being able to declare war?