Eclipse editor won't open
This is often a problem with temporary files saved by eclipse plugins. Check YOUR_WORKSPACE/.metadata/.plugins/org.eclipse.jdt.core/ There are a lot of index files. Sometimes it helps to delete them. Also start your eclipse with -clean.
But i think your problem is slightly different. Did you have a reference to a library(jar-file) somewhere in your filesystem? If you deleted it or moved it, eclipse can't build your projects.
You refreshed all your projects?
Best regards Florian
I've got the same problem though my eclipse is much newer - 4.2 (Juno). For me the solution was to remove <workspace>/.metadata/.plugins/org.eclipse.core.resources/.snap. Afterwards I found this bug in eclipse.org: Bug 178988 - Crash at startup due to ".snap" files.
Hope this will help somebody.
at org.eclipse.core.runtime.Path.<init>(Path.java:183)
at org.eclipse.core.internal.resources.WorkspaceRoot.getProject(WorkspaceRoot.java:181)
at org.eclipse.jdt.internal.core.ExternalFoldersManager.isExternalFolderPath(ExternalFoldersManager.java:90)
at org.eclipse.jdt.internal.core.JavaProject.addToResult(JavaProject.java:2738)
at org.eclipse.jdt.internal.core.JavaProject.resolveClasspath(JavaProject.java:2688)
The stack trace seem to indicate that there is a problem with your classpath.
- Maybe your JRE is pointing to an invalid location / isn't defined? (Window->Preferences->Java->Installed JREs).
- Maybe your project contains invalid class path entries? Try to create a new java project and check if that is working as expected. If it works check the classpath of your not working project.
Edit: Another Idea ... launch eclipse on an other workspace. Then create a launch configuration for an "Eclipse Configuration" with the workspace that produces an error. Set a java exception breakpoint for NullPointerException. Start in debug mode and you can inspect the variables to see which path produces the problems.