I was messing around with a lot of mods yesterday. I updated my ATI graphics and installed shaders. This was a huge complicated task but well worth it. I installed the baby animals mod, made some more maps, installed a sound mod, tried out invedit, etc...
I did a lot of stuff and somewhere in there I crashed my millenaire mod. I couldn't trade with the villagers anymore.
Then I started getting this error:
After a lot of sleuthing (the minecraft forum was down) what I found was that the new millenair isn't compatible with the old villages.
This is some of what the log said:
0.5.4 19-05-2011 04:04:40 ERROR: townhall_0 at 2057/69/-328/2/1 Sept-Frères-le-lac: Exception in TileEntityBuilding.onUpdate():
0.5.4 19-05-2011 04:04:40 Exception, printing stack:
0.5.4 19-05-2011 04:04:40 java.lang.NullPointerException
at java.lang.Thread.run(Unknown Source)
I had to go around to the villages and burn down then hack apart the town halls. It was fun - I felt a little like a conquistador beating on the locals. The locked chests take a while to hack apart. They seem to be obsidian or something.
Once I destroyed the town hall the error went away. The villagers built new town halls and relations with the natives resumed as normal.
There is a different solution posted on the Millénaire - NPC village forum thread (now that it's back up and running) but I think my solution has a certain sadistic charm that is well worth it.
Addendum: Unfortunately the villagers all disappeared on me after I left the game. I had to restore a saved game that didn't have the baby animals mod to get them back.