We had the same trouble, but now it works.
- We could see the builder after we tried to build our first project within the dev space, but wasn't able to build it. (waited some minutes)
- We restarted the di-core more times, but didn't changed the situation
- More times we created a new project and tried to build it again, but it failed.
- Saw that there were some Divx apps not started, so I started them
- After that I restarted di-core again and it worked.
But really, I'm not sure what in the end did the trick. We are glad that it works now. 