今天遇到该问题，clean and rebuild 不行。
Tools->Options->Debugging->General->去掉Require source files to exactly match the original version之前的勾即可。
我怀疑可能是输入某些不兼容的编码导致，因为在编译信息中发现一个警告：
warning C4819: The file contains a character that cannot be represented in the current code page (936). Save the file in Unicode format to prevent data loss。。。