I had a project added in Eclipse Force.com IDE, which was working fine.
Then I removed the project and added it back. This time I got a null pointer error:
Here's a paste of the logfile (from workspace/.metadata/.log:
Googling, I see this problem has been around for several years.
I've tried rolling back to Java 6, which seems to be the most popular internet solution. This doesn't work. I've tried uninstalling everything Eclipse related, and reinstalling. This doesn't work.
ETA: Just tried rolling back to Java 6 update 27. Still no good.
NB The credentials work. The instance host is not reporting any issues on https://trust.salesforce.com/trust/status/
Using Eclipse Keplar on Windows 7.