Indeed FallbackCulture has no effect as Wix# compiler does not rely on VS project infrastructure (so it's possible to compile MSI without using VS at all).
You are also right that project.Language is the value that gets passed to light.exe with "-culture" option. However the current implementation does not allow multiple languages to be specified and this is the problem for the cases like yours. Unfortunately there is no a good work around. The only thing you can do is to call BuildMsiCmd instead of BuildMsi and then modify the produced batch file to include extra culture for the "-culture" option. But it is a clumsy work around.
If you don't want to wait for the next release you can use the 'HotFix' NuGet release v1.0.27.1 that has support for multiple languages (e.g.
You can get it with this NuGet command:
You are also right that project.Language is the value that gets passed to light.exe with "-culture" option. However the current implementation does not allow multiple languages to be specified and this is the problem for the cases like yours. Unfortunately there is no a good work around. The only thing you can do is to call BuildMsiCmd instead of BuildMsi and then modify the produced batch file to include extra culture for the "-culture" option. But it is a clumsy work around.
If you don't want to wait for the next release you can use the 'HotFix' NuGet release v1.0.27.1 that has support for multiple languages (e.g.
Project.Language="en-US,en-AU"). You can get it with this NuGet command:
Install-Package WixSharp.bin -Pre