County title becomes vacant when two people inherit simulataneously

[richvh]

This happened in an observe game I ran on the mod I'm maintaining (Lux Invicta):

The province is now black and unclickable. How this happened I have no idea but it seems to be related to two people inheriting it simultaneously, as this is also the same date it gets no holder. Mod is here and savegame is here.

 

[richvh]

A little more information I gathered:

All baronies in c_philippopolis have holders, just the county title is vacant.

c_philippopolis had two holders starting in 1356, as did some other counties, but only c_philippopolis has the triple with "0" (no holder)

Titles affected by the death of 311255 Athanasios the Bold in 1356:

Spoiler

d_armeniacon:

			1318.12.16=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1356.2.9=
			{
				holder=326712
			}
			1391.6.13=
			{
				holder=333962
			}
			1394.2.7=
			{
				holder=340283
			}
			1395.6.24=
			{
				holder=347151
			}

c_amisos:
[ 1318.12.14=
{
holder=311255
}
1356.2.8=
{
holder=317353
}
1358.9.14=
{
holder=319080
holder=326712
}
1391.6.13=
{
holder=333962
}
1394.2.7=
{
holder=340283
}
1395.6.24=
{
holder=347151
}
1445.7.14=
{
holder=358580
}[/code]
c_sinope:

			1291.2.14=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
				holder=326712
			}
			1391.6.13=
			{
				holder=333962
			}
			1394.2.7=
			{
				holder=342931
			}
			1438.6.2=
			{
				holder=352814
			}

e_byzantium:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}

c_adrianopolis:

			1291.2.14=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
				holder=337295
			}
			1405.9.6=
			{
				holder=345266
			}

c_philippopolis:

			1291.2.14=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
				holder=327149
			}
			1400.5.7=
			{
				holder=335406
				holder=330739
				holder="0"
			}

c_kaiseria:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
				holder=337295
			}
			1405.9.6=
			{
				holder=345266
			}

d_thrace:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}

c_kaliopolis:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}

c_thrake:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}

d_turnovo:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}

c_tyrnovo:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}
c_serdica:

1345.5.1=
{
holder=311255
}
1356.2.8=
{
holder=317353
}
1358.9.14=
{
holder=319080
}
1364.1.29=
{
holder=320097
}
1379.8.23=
{
holder=320285
}
1381.5.25=
{
holder=322792
}
1383.8.21=
{
holder=324673
}
1400.4.14=
{
holder=327149
}[/code]
c_dorostotum:

			1345.5.1=
			{
				holder=311255
			}
			1356.2.8=
			{
				holder=317353
			}
			1358.9.14=
			{
				holder=319080
			}
			1364.1.29=
			{
				holder=320097
			}
			1379.8.23=
			{
				holder=320285
			}
			1381.5.25=
			{
				holder=322792
			}
			1383.8.21=
			{
				holder=324673
			}
			1400.4.14=
			{
				holder=327149
			}

As you can see, not all of the titles held by Athanasios had dual inheritors, and some other titles had dual inheritors not directly affected by Athanasios's death.