无法找到或加载主 class com.liferay.portal.tools.SassToCssBuilder

Could not find or load main class com.liferay.portal.tools.SassToCssBuilder

我正在使用 Liferay 6.2 CE。当我部署我的 portlet 时,显示了这条错误消息。

Buildfile: /home/matej/liferay-plugins-sdk-6.2/portlets/RegistrationForm-portlet/build.xml
war:
     [java] Error: Could not find or load main class com.liferay.portal.tools.SassToCssBuilder

BUILD FAILED
/home/matej/liferay-plugins-sdk-6.2/build-common.xml:2468: The following error occurred while executing this line:
/home/matej/liferay-plugins-sdk-6.2/build-common.xml:2473: The following error occurred while executing this line:
/home/matej/liferay-plugins-sdk-6.2/build-common.xml:322: The following error occurred while executing this line:
/home/matej/liferay-plugins-sdk-6.2/build-common.xml:2104: The following error occurred while executing this line:
/home/matej/liferay-plugins-sdk-6.2/build-common.xml:175: Java returned: 1

Total time: 5 seconds

昨天一切正常...我完成了工作,保存了进度并关闭了 eclipse。今天,在用我的项目打开 eclipse 后,显示了这个错误消息。我用的是liferay-plugins-sdk-6.2,所以不知道问题出在哪里。我将不胜感激任何帮助。

请阅读here。同样的问题。