Eclipse editor won't open

Question

My Eclipse cannot show the editor window.

Error:

Could not open the editor: The editor class could not be instantiated. This

Answer 1

Removing the index files as suggested by others didn't help in my case. I had to reset the perspective: right-click the "Java" perspective toggle button in the upper right corner, choose "Reset". At least it's better than recreating the entire workspace.

Answer 2

I was getting this for FlashBuilder 4.7. It was a permissions issue. On Mac OSX, from the info box, I gave my user READ & WRITE access to Flash Builder 4.7 folder, then did "Apply to enclosed items..." and that fixed it.

Answer 3

Here was simple. Right-click in the class and choose the / open with / Java Editor, or Generic Text Editor option.

Aqui foi simples. Clique na classe com o botão direito e escolha a opção / open com / Editor Java, ou Editor de Texto Genérico.

Answer 4

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

Answer 5

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.

1. Maybe your JRE is pointing to an invalid location / isn't defined? (Window->Preferences->Java->Installed JREs).
2. 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.

Answer 6

Had the same problem(on Indigo 3.7) and getting right version of jadclipse jar(net.sf.jadclipse_3.3.0.jar with Jad 1.5.8g) did it for me