I get an intermittent error when launching Eclipse with an open GAE project. It prevents me from building my project. I can sometimes get it to clear by deleting the contents of the "war/WEB-INF/classes" folder and then restarting Eclipse. Sometimes I close the project, close eclipse, launch eclipse, open the project and that seems to help. The error has been happening for several months and has persisted through a GAE plugin upgrade. I can usually get Eclipse to work eventually. Once it works it keeps working great until I relaunch it.
I am using GAE appengine-java-sdk-1.6.3 GWT 2.4.0 Objectify 3.1 (love it) Eclipse Indigo SR2 Windows 7 64-bit
It feels like maybe a race condition when starting Eclipse.
Any ideas?
These errors occur during the build ======================
Errors running builder 'Java Builder' on project '*'. com/google/appengine/eclipse/core/nature/GaeNature
Errors running builder 'Google WebApp Project Validator' on project '*'. java.lang.NullPointerException
Error instantiating builder 'com.google.appengine.eclipse.core.projectValidator'.
Plug-in com.google.appengine.eclipse.core was unable to load class com.google.appengine.eclipse.core.validators.GaeProjectValidator.
An error occurred while automatically activating bundle com.google.appengine.eclipse.core (841).
Plug-in com.google.appengine.eclipse.core was unable to load class com.google.appengine.eclipse.core.validators.GaeProjectValidator.
An error occurred while automatically activating bundle com.google.appengine.eclipse.core (841).
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I also got this error when trying to open the Google/App Engine properties dialog in Eclipse
Unable to create the selected property page. An error occurred while automatically activating bundle com.google.appengine.eclipse.core (841).