Error when opening package explorer and when trying to open java classes in Eclipse

Getting this strange error in Eclipse (Helios). I can't show the package explorer.

Could not create the view: org/eclipse/jdt/internal/corext/codemanipulation/tostringgeneration/ToStringGenerationSettings (wrong name: org/eclipse/jdt/internal/corext/codemanipulation/tostringgeneration/ToStringGenerationSettings$CustomBuilderSettings)

Same error when trying to open a java class file.开发者_运维问答 Any clues?

Agreed with Arne's and Gilbert's comments. If this is still an issue, a few things you can try to resolve:

• Try a new workspace (using the same Eclipse installation).
• Trying a new Eclipse installation (using your same workspace). This would also be a good chance to upgrade to the latest version of Eclipse, now 3.7 / Indigo.

(Primarily posting this answer in an attempt to either get this question some additional attention / competitive answers, or at the least, to simply remove this from the growing list of unanswered questions.)