eclipse运行错误提示 Failed to load D:\Android\sdk\build-tools\26.0.0-preview\lib\dx.jar

前几天在ecplise上运行项目还好好，今天一运行就提示这个错误：Your project contains error(s), please fix them before running your application.（你的程序包含错误，请修改后再运行）。咋一看，以为代码哪里写错了，我是左改右改，上改下改......还是提示这个错误，心都碎了：

控制台是这样输出的：

[2017-03-28 22:11:52 - Dex Loader] Failed to load D:\Android\sdk\build-tools\26.0.0\lib\dx.jar
[2017-03-28 22:11:52 - api19] Unknown error: Unable to build: the file dx.jar was not loaded from the SDK folder!
[2017-03-28 22:12:11 - Dex Loader] Failed to load D:\Android\sdk\build-tools\26.0.0\lib\dx.jar
[2017-03-28 22:12:11 - api19] Unknown error: Unable to build: the file dx.jar was not loaded from the SDK folder!

 

提示dx.jar文件没加载到，按网上一些方法试了也不行，我就找到D:\Android\sdk\build-tools\这个目录，目录如下图，我想，既然他找不到26.0.0这个文件夹，那我就把它删了。我把26.0.0文件夹剪切放到别的位置备份，以免出错再恢复回来。再次打开eclipse运行就成功了，哈哈，我太聪明了

删了后的目录图：