It took some digging, but I was able to start scripting a wrapper in C# for the RPC commands.
C# Wrapper (MTConnect Implementation)
Unofficial JSON-RPC Reference
I still don't understand what every method does to the machine or necessarily what the results are, so a number of the methods are marked as obsolete until I can test them.
Exactly what software are you using to slice? From your description, it appears the gcode was successfully generated, but the software choked when trying to draw teh preview image. That could be due to lack of local RAM or problems with memory leaks in the software. This happens when the number of layers and the complexity of the layers gets large.
It might be this board, MakerBot 5th Generation motherboard, (original image)
The image was very small, so it is rather blurry, I'm afraid.
I have contacted the suppliers for confirmation, and will update this answer, when/if I get a reply.
However, according to this eBay item, Makerbot Replicator Motherboard Carriage, it could be inferred1 that the same ...
The Mystery of Makerbot-Wiki
According to the Wayback machine, the wiki.makerbot.com went offline on 31st December 2012:
Over the past three amazing years, MakerBot owners and enthusiasts around the world have shared knowledge with us and with each other. As we welcome thousands more MakerBot owners and users into the MakerBot family, we want to make ...