There seems to be a bug where potential marriage candidates are hidden and/or locked from the player - i.e. the player can't initiate a union (marriage) between two characters, however the AI is capable of demanding or offering a union.
I noticed this when Liu Bei offered a union between one of his general's and Sun Ren. When I decided to alter the deal slightly I found i couldn't actually select the option to offer or receive a marriage.
Keep in mind this is happening in the same turn. So it isn't a situation where the original candidate has been offered up somewhere else or married between the turn cycle.Build Number (this can be found in the top right hand corner of the menu screen)
v1.1.0 Build 9626.1677051 (Beta Patch)Detailed description of your issue
See Above.Reproduction steps
You need a marriage candidate late into the campaign. I'm not entirely sure when this starts to occur, and I unfortunately no longer have a save file that can highlight this issue. If I run into it again on another play through I will post it here. Screenshots demonstrating the problem:Figure 1: Liu Bei offering a candidate:
Figure 2: Trying to negotiate for a better candidate but I cannot select the diplomacy option: