Could not find version number data in TF_BUILD_BUILDNUMBER

Hi,

I'm using the default build process template TfvcTemplate.12.xaml that came with TFS2013. I'm trying to call ApplyVersionToAssemblies.ps1 (from the Community TFS Build Extensions) in the pre-build script to version assemblies. In lieu, I got this error below.

ApplyVersionToAssemblies.ps1 : Could not find version number data in TF_BUILD_BUILDNUMBER.
+ CategoryInfo : NotSpecified: (:) [Write-Error], WriteErrorExcep
tion
+ FullyQualifiedErrorId : Microsoft.PowerShell.Commands.WriteErrorExceptio
n,ApplyVersionToAssemblies.ps1

I've read that TF_BUILD environment variables are automatically created, but I do not see them in the build machine. Do I need to manually create those variables?

TDN