“no classfiles specified Conversion to Dalvik format failed with error 1”
or
Android requires .class compatibility set to 5.0. Please fix project properties.
解决方法：
1： 选择 project -> Android Tools ->Fix Project Properties.
重新 clean project
2：如果上面不管用，只能使用暴力一点的方法，复制源代码到信的目录. 包括AndroidManifest.xml, src/, assets/, res/. 选择 File-> New-> Android Project -> Contents -> Create project from existing source -> <your new location>