在Visual Studio 2015中调试php项目时出错

I am Creating a PHP project in visual studio 2015 with php tools for Visual Studio, But facing an error saying You Environment is missing php5.6 with debugging extensions enter image description here
when i click ok, it opens a download window Console, here i am facing another Error which is: enter image description here
the question is: Why am I facing these Error? and How can i resolve these Errors? Thanks!