Describe the bug
I don't know for sure this is a bug in MCA, so I'm asking more for how I might troubleshoot the issue. MCA is the most obvious place to start to me. My villages are populated when I reach them, but the villagers quickly evaporate. I spawn some more with eggs, they quickly evaporate. (like 10-20 mins later) This has been happening for me from MCA 6.0.1 through the current 6.1.0.

Steps to Reproduce
Please include steps we can take to reproduce the bug:

1. Launch Minecraft.
2. Log in to custom server I created.
3. Find any village.
4. Watch existing villagers for a few minutes, they'll walk around a corner or something and disappear.
5. Spawn more villagers inside buildings with villager eggs, they walk away and quickly disappear.

Minecraft Information (please complete all questions entirely):

• Minecraft Version: 1.12.2
• Forge Version: 14.23.5.2847
• MCA Version: 6.1.0 (also occurred with 6.0.1)
• Launcher: Standard

Modpack Information
Complete this section if you are using a modpack.

• Modpack Name: [e.g. FTB Infinity]
• Modpack Version: [e.g 3.1.0]

Mods List
Complete this section if you are NOT using a modpack but have other mods installed alongside MCA.

• Please list the other mods you have installed
  ** Client Side:

1. AdChimneys-1.12.2-3.5.7.0-build.0424.jar
2. Advanced+Machines-61.0.1.jar
3. Advanced+Solar+Panels-4.3.0.jar
4. AmbientEnvironment-1.0.2.jar
5. AmbientSounds_v3.0.9_mc1.12.2.jar
6. animania-1.12.2-1.7.2.jar
7. appliedenergistics2-rv6-stable-7.jar
8. AppliedIntegrations-1.12.2-3cd3ad3c.jar
9. artisanintegrations-1.12.2-1.1.2.jar
10. artisanworktables-1.12.2-1.22.13.jar
11. athenaeum-1.12.2-1.17.4.jar
12. Baubles-1.12-1.5.2.jar
13. bdlib-1.14.3.12-mc1.12.2.jar
14. betteranimalsplus-1.12.2-7.1.1.jar
15. bettercaves-1.12.2-1.5.1.jar
16. BetterSigns-1.0_v1.12.2.jar
17. BiomesOPlenty-1.12.2-7.0.1.2443-universal.jar
18. BloodArsenal-1.12.2-2.2.1-29.jar
19. BloodMagic-1.12.2-2.4.3-105.jar
20. BluePower-1.12.2-0.3.148-universal.jar
21. bookworm-1.12.2-2.3.0.jar
22. Botania+r1.10-362.jar
23. buildcraft-all-7.99.24.3.jar
24. CD4017BE_lib-1.12.2-6.4.13.jar
25. Chameleon-1.12-4.1.3.jar
26. ChickenDropFeathers-1.0.jar
27. Chisel-MC1.12.2-1.0.0.42.jar
28. CodeChickenLib-1.12.2-3.2.3.358-universal.jar
29. CommonCapabilities-1.12.2-2.4.4.jar
30. CompactDrawers-1.12.2-1.0.5.125.jar
31. CraftStudioAPI-universal-1.0.1.95-mc1.12-alpha.jar
32. CreativeCore_v1.9.68_mc1.12.2.jar
33. CTM-MC1.12.2-1.0.0.29.jar
34. CustomMobSpawner-3.11.4.jar
35. CyclopsCore-1.12.2-1.5.1.jar
36. DeathQuotes-1.2.0-mc1.12-forge.jar
37. DoggyTalents-1.12.2-1.15.1.4-universal.jar
38. DrZharks MoCreatures Mod-12.0.5.jar
39. DynamicSurroundings-1.12.2-3.6.0.2.jar
40. DynamicTrees-1.12.2-0.9.6.jar
41. DynamicTreesBOP-1.12.2-1.4.1e.jar
42. DynamicTreesPHC-1.12.2-1.4.2.jar
43. DynamicTreesTC-1.12.2-1.4.1e.jar
44. EnderCore-1.12.2-0.5.72.jar
45. EnderIO-1.12.2-5.1.52.jar
46. EnderIO-endergy-1.12.2-5.1.52.jar
47. Exotic+Birds+1.12.2-3.0.0.jar
48. ExtendedDays-1.12.2-0.2.9-28.jar
49. extrabows-v1.12.2+b10.jar
50. forestry_1.12.2-5.8.2.409.jar
51. ForgeEndertech-1.12.2-4.4.24.0-build.0421.jar
52. Forgelin-1.8.4.jar
53. ForgeMultipart-1.12.2-2.6.2.83-universal.jar
54. furniture-6.3.1-1.12.2.jar
55. GasConduits-1.12.2-1.2.2.jar
56. generators-0.9.20.12-mc1.12.2.jar
57. gravestone-1.10.3.jar
58. Guide-API-1.12-2.1.8-63.jar
59. Harvest-1.12-1.2.7-20.jar
60. Hwyla-1.8.26-B41_1.12.2.jar
61. ImmersiveEngineering-0.12-92.jar
62. InductiveLogistics-1.12.2-1.3.4.jar
63. industrialcraft-2-2.8.187-ex112.jar
64. IntegratedCrafting-1.12.2-1.0.8.jar
65. IntegratedDynamics-1.12.2-1.1.0.jar
66. IntegratedTerminals-1.12.2-1.0.11.jar
67. IntegratedTunnels-1.12.2-1.6.10.jar
68. InventoryTweaks-1.64+dev.146.jar
69. jei_1.12.2-4.15.0.292.jar
70. JustEnoughIDs-1.0.3-48.jar
71. logisticspipes-0.10.2.208.jar
72. Mantle-1.12-1.3.3.55.jar
73. MCA-1.12.2-6.1.0-universal.jar
74. mcmeds_1-12-2_v2.jar
75. mcpaint-1.2.4.jar
76. Mekanism-1.12.2-9.8.2.389.jar
77. MJRLegendsLib-1.12.2-1.1.9.jar
78. MrTJPCore-1.12.2-2.1.3.35-universal.jar
79. nps_1.12-2.1.jar (Nether Portal Spread)
80. OpenComputers-MC1.12.2-1.7.4.153.jar
81. OptiFine_1.12.2_HD_U_F4.jar
82. OreLib-1.12.2-3.6.0.1.jar
83. Pam's+HarvestCraft+1.12.2zf.jar
84. ProjectRed-1.12.2-4.9.1.92-Base.jar
85. ProjectRed-1.12.2-4.9.1.92-compat.jar
86. ProjectRed-1.12.2-4.9.1.92-fabrication.jar
87. ProjectRed-1.12.2-4.9.1.92-integration.jar
88. ProjectRed-1.12.2-4.9.1.92-lighting.jar
89. ProjectRed-1.12.2-4.9.1.92-world.jar
90. railcraft-12.0.0.jar
91. refinedstorage-1.6.15.jar
92. Rex's-Additional-Structures-1.12.x-(v.2.3.1).jar
93. SereneSeasons-1.12.2-1.2.18-universal.jar
94. SilentLib-1.12.2-3.0.13+167.jar
95. sit-1.12.2-v1.2.3.jar
96. StorageDrawers-1.12.2-5.4.0.jar
97. StorageDrawersExtras-1.12-3.1.0.jar
98. TConstruct-1.12.2-2.13.0.171.jar
99. Thaumcraft-1.12.2-6.1.BETA26.jar
100. Thaumic+Arcana-1.3.0.jar
101. ThaumicAugmentation-1.12.2-1.1.11.jar
102. thaumicwonders-1.8.2.jar
103. unifier-3.0.4.jar
104. UnlimitedChiselWorks-0.3.0.jar
105. WearableBackpacks-1.12.2-3.1.4.jar
106. XaerosWorldMap_1.5_Forge_1.12.jar
107. Xaeros_Minimap_1.18.8_Forge_1.12.jar

** Server-only mods:

1. DiscordChat-1.12.2-2.3.0.jar
2. Morpheus-1.12.2-3.5.106.jar

Additional context
Add any other context about the problem here that you feel is useful. Screenshots, world files, logs, etc.

"Happy to supply anything that might be useful. I'm wondering what my next steps should be to troubleshoot this kind of issue. Is there a way to log despawns, to see what caused it? I'm certain they're not being killed, it's broad daylight, with no mobs nearby when they despawn."

I'm heavily considering closing this ticket. I started another server, new world, same mods, new config (so nothing edited by me) and the villagers are remaining. I don't know what config option I might've enabled to cause the villagers to expire so quickly in that world, but it doesn't appear to be a legit bug in MCA, so I'll probably close the issue, if you don't beat me to it.