NullPointerException in eclipse in Eclipse itself at PartServiceImpl.internalFixContext

There is a bug filed for Eclipse:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=385680

You could try restarting Eclipse, it helped the original poster of the issue there.

Better you update your eclipse by clicking it on help >> check for updates, also you can start eclipse by entering command in command prompt eclipse -clean.
Hope this will help you.

hi，that maybe the project's problem,

chose the project and setting you eclipse:

project -> clean...