wav and flac

As i do renaming the existing .wav file, i receive this error message after i click a left mouse button in Unity project.

FileNotFoundException: Could not find file "New Unity Project 2\Assets\StreamingAssets\Flac\testwav.flac". System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.IO/FileStream.cs:305) System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share) (wrapper remoting-invoke-with-check) System.IO.FileStream:.ctor (string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare) System.IO.File.OpenRead (System.String path) (at

I am using an audio source and audio mixer as part of the microphone for the user.