当我尝试在eclipse indigo中打开android项目时显示以下错误，但是第一次它正常工作：
Errors occurred during the build.
Error instantiating builder 'com.android.ide.eclipse.adt.ResourceManagerBuilder'.
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.build.builders.ResourceManagerBuilder.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (1043).
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.build.builders.ResourceManagerBuilder.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (1043).
Error instantiating builder 'com.android.ide.eclipse.adt.PreCompilerBuilder'.
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.build.builders.PreCompilerBuilder.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (1043).
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.build.builders.PreCompilerBuilder.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (1043).
Error instantiating builder 'com.android.ide.eclipse.adt.ApkBuilder'.
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (1043).
Plug-in com.android.ide.eclipse.adt was unable to load class c com.android.ide.eclipse.adt.internal.build.builders.PostCompilerBuilder.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (1043).
任何想法都值得赞赏。
提前致谢。