[wix-users] Wix Msbuild issue

[Laique Abbas]

I am getting an error stated below :
light.exe : error LGHT0103: The system cannot find the file '{Filename}' with type ''.
Though this {Filename} exists on physical path.
Is there a problem with my Define constant property as I have provided 2 variables in it ?
I am using msbuild.exe. I am providing 2 define constants variable in the below line : I am breaking my msbuild line for clarity purposes for this email :
 & C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe /property:configuration="Debug" /property:Platform="Any CPU" /property:OutputPath=$outputPath /property:Version=$version "/property:DefineConstants=`"ServiceSourcePath="abc";SourcePath="xyz"`"" $solution /m /target:build 
Can any one help me figure out whats the issue ?
Regards,Laique