今天遇到該問題，簡單的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。
我懷疑可能是輸入某些不兼容的編碼導致，因爲在編譯信息中發現一個警告：
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。。。