strange heir change

[mlsmith45]

I'm playing as the Byz Emperor. I've landed my heir with some counties and titles. My second son is married to a duchess in the realm. They are both born in the purple. My first son was my heir for years, when suddenly it changed to my second son without explanation.

The only two things I can figure that might affect it is that my first son was briefly jailed, but is now released. But it never changed back. Or I'm impatient and hasn't done so yet. The change in heir happened around that time. The first son is married to duchess outside of the realm. His son is listed as the heir to many of my other titles, skipping him. The byz empire doesn't allow for external inheritance, while the other titles do. But if this applied, why wasn't this the case from day one? And why is the grandson okay to inherit?

Anyway here is the saved game, if anyone has a moment to look at and figure it out. It's frustrating, because it's thrown my entire plan into disarray. This is fine as a challenge, but I'd like to know what happened.

Here's my HIP version info:

[HIP 2014-12-23]
Enabled HIP modules:
ARKO Armoiries (2014-12-05)
ARKO Interface (2014-12-05)
Project Balance (v5.0 - 2014-12-17)
SWMH - Native localisation (v2.854 - 2014-04-12)
NBRT+ (v2.1 - 2014-03-28)
VIET Events (v1.9.0 - 2014-12-18)
EMF: Extended Mechanics & Flavor (v3.02 - 2014-12-23)

I play with all dlcs except the aztecs and charlemagne.

 

[mlsmith45]

I just figured it out, whoever jailed him castrated him, so now he's a Eunich and can't rule?? Bastard who jailed him.

 

[zijistark]

Them Byzantines mean serious business. One of the better games I've played in my recent past involved my perfect young later-to-be Shahanshah-Caliph getting blinded by the Byzantines after being captured in battle. Fuckers. My whole game became about shattering their empire after that. But, yeah, at least they didn't castrate me.