Wix bootstrapper webinstaller does not download msi-file

Question

In my bootstrapper I want to install one package as a webinstallation. Therefore I added the following MsiPackage to the Bundle´s Chain

      <MsiPackage DisplayInternalUI="yes" Visible="yes" Id="NodeJs"
              Compressed="no"
              ForcePerMachine="yes"
              SourceFile="node-v0.10.32-x86.msi"
              DownloadUrl="https://nodejs.org/dist/v0.10.32/node-v0.10.32-x86.msi">
        <MsiProperty Name="INSTALLFOLDER" Value="[Global_InstallFolder]\NodeJs" />

However, the installation only works as expected when the to-download-msi-file is in the same directory as the bootstrapper-exe. In other words, it does not download the msi-file.

What am I doing wrong?