The project was not built due to "Could not delete '/XXX/WebRoot/WEB-INF/classes/library'.". Fix the problem, then try refreshing this project and building

在构建插件时提示如下错误：

Description Resource Path Location Type The project was not built due to "Could not delete '

在网上查找时发现，最简单的解决方法是：project-->clean，选择出错的工程，点击确定错误即可消除。