Eclipse - The project was not built due to "Could not delete
因為上次的亂搬動jar檔後，
結果這次run其它專案也發生問題，
這次Console窗格，出現「錯誤: 找不到或無法載入主要類別」，
而Problems錯誤訊息則顯示 「The project was not built due to "Could not delete ....」
查了網路文章
http://felixhuang.pixnet.net/blog/post/26615315-%5Beclipse%5D-the-project-was-not-built-due-to-%22could-not-delete
就是要去執行Project> Clean的動作，就可以了。