[NFP] Open Borders missing from trade screen

[smvalentine]

I'm not sure if this is a bug or I've just missed something.
(And I started this game with no mods, enabled a bunch of UI mods and played for a while, then when I found this I turned the mods off (and restarted the game).)

One Civ (Gilgamesh) doesn't have Open Borders on the trade screen (on either side) even though they've got solid borders. We're not at war (he's displeased with me), not friends or allies, no emergency in effect.
I've been able to get open borders from all the other civs. He has denounced me, but thought I'd gotten open borders from others while denounced.

Has anyone else seen this?

 

[Kibikus]

He has denounced me, but thought I'd gotten open borders from others while denounced.

Nope, no open borders when denounced.

 

[newbie2]

how do you get denounced by Gilgabro?

 

[smvalentine]

how do you get denounced by Gilgabro?

Playing as Norway and doing a lot of pillaging was enough for me.