我觉得这就像是adb的大姨妈一样，不过处理起来还是很easy滴：
1.报错：BUILD FAILEDD:workspaceganjiuild.xml:144: The following error occurred while executing this line:D:workspaceganjiuild.xml:271: Unable to delete file D:workspaceganji mpproguard mp.jar解决：已经开了一个模拟器了，无法重新编译，必须关闭一个。
2.报错：The connection to adb is down, and a severe error has occured.解决：cmd跳到sdk tools文件路径下adb kill-server然后再adb start-server或者：右键项目mdash;mdash;gt;Android Tools mdash;mdash;gt;Fix Project Properties，再run。
3.报错：The connection to adb is down, and a severe error has occured.[2010-03-11 09:36:56 - HelloOPone] You must restart adb and Eclipse.[2010-03-11 09:36:56 - HelloOPone] Please ensure that adb is correctly located at #39;D:OPhoneSDK_1.5platform-toolsadb.exe#39; and can be executed.
解决：方法1.cmd中adb kill-server，然后adb -startserver方法2.方法1不管用，那么在任务管理器中杀死adb.exe，然后重启Eclipse。方法3.方法1和2都不管用，那么查看最后一句报错中：platform-tools中是否有adb.exe（或者在相关路径下面有没有platform-tools文件夹，如果没有，选择新建一个文件夹，并且把tools中的文件全部复制到platform-tools中）
转载：http://www.xinyuedi.net/androidkaifa/608.html（我用的方法二，good。。。）