Project wont build - Error building Player: ArgumentException: An empty file name is not valid.

Questions & Answers
1

Im using windows and building for windows phone. When building i get 2 errors:

Error building Player: ArgumentException: An empty file name is not valid.
Parameter name: sourceFileName

ArgumentException: An empty file name is not valid.
Parameter name: sourceFileName
System.IO.File.Copy (System.String sourceFileName, System.String destFileName, Boolean overwrite) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.IO/File.cs:98)
System.IO.File.Copy (System.String sourceFileName, System.String destFileName) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.IO/File.cs:86)
PostProcessWSA.CopyTestCertificate () (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/PostProcessWSA.cs:231)
PostProcessWinRT.Process () (at C:/buildslave/unity/build/PlatformDependent/WinRT/SharedSources/CSharp/PostProcessWinRT.cs:141)
UnityEditor.Metro.BuildPostprocessor.PostProcess (BuildPostProcessArgs args) (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/ExtensionModule.cs:133)
UnityEditor.PostprocessBuildPlayer.Postprocess (BuildTarget target, System.String installPath, System.String companyName, System.String productName, Int32 width, Int32 height, System.String downloadWebplayerUrl, System.String manualDownloadWebplayerUrl, BuildOptions options, UnityEditor.RuntimeClassRegistry usedClassRegistry) (at C:/buildslave/unity/build/Editor/Mono/BuildPipeline/PostprocessBuildPlayer.cs:316)
UnityEditor.BuildPlayerWindow:BuildPlayerAndRun()

3

I got this error because I didn’t setup properly the WSA certificate in Edit → Project Settings → Player → Windows Store → Publishing → Certificate. For some reason it was empty. I just chose my existing certificate and built it again successfully. Otherwise, you can try to create a new certificate and select it.

2

Ok, i found a solution. A dumb one, but it seems to work. You need to create a new project and copy assests from the old one, while building it constantly (copying all assests at once gives the same error).