title: System.DLLNotFoundException: fusion.dll
body: <p>I'm building an application using Godot with C# support (Mono).</p>
  
  <p>Building the solution in Visual Studio works fine, no errors. However, trying to build the application with Godot throws an exception : </p>
  
  <pre><code>C:\Program Files\Mono\lib\mono\msbuild\15.0\bin\Microsoft.Common.CurrentVersion.targets(2130,5): error MSB4018: The "ResolveAssemblyReference" task failed unexpectedly.
  System.DllNotFoundException: fusion.dll
    at (wrapper managed-to-native) Microsoft.Build.Tasks.NativeMethods.CompareAssemblyIdentityWindows(string,bool,string,bool,bool&amp;,Microsoft.Build.Tasks.NativeMethods/AssemblyComparisonResult&amp;)
    at Microsoft.Build.Tasks.NativeMethods.CompareAssemblyIdentity (System.String assemblyIdentity1, System.Boolean fUnified1, System.String assemblyIdentity2, System.Boolean fUnified2, System.Boolean&amp; pfEquivalent, Microsoft.Build.Tasks.NativeMethods+AssemblyComparisonResult&amp; pResult) [0x00007] in &lt;050f973d2a7f41969411264f5f4b2cfa&gt;:0 
    at Microsoft.Build.Tasks.ReferenceTable.ResolveAssemblyNameConflict (Microsoft.Build.Tasks.AssemblyNameReference assemblyReference0, Microsoft.Build.Tasks.AssemblyNameReference assemblyReference1) [0x000c4] in &lt;050f973d2a7f41969411264f5f4b2cfa&gt;:0 
    at Microsoft.Build.Tasks.ReferenceTable.ResolveConflictsBetweenReferences () [0x0003a] in &lt;050f973d2a7f41969411264f5f4b2cfa&gt;:0 
    at Microsoft.Build.Tasks.ReferenceTable.ResolveConflicts (System.Collections.Generic.List`1[Microsoft.Build.Tasks.DependentAssembly]&amp; idealRemappings, System.Collections.Generic.List`1[Microsoft.Build.Tasks.AssemblyNameReference]&amp; conflictingReferences) [0x00006] in &lt;050f973d2a7f41969411264f5f4b2cfa&gt;:0 
    at Microsoft.Build.Tasks.ResolveAssemblyReference.Execute (Microsoft.Build.Shared.FileExists fileExists, Microsoft.Build.Shared.DirectoryExists directoryExists, Microsoft.Build.Tasks.GetDirectories getDirectories, Microsoft.Build.Tasks.GetAssemblyName getAssemblyName, Microsoft.Build.Tasks.GetAssemblyMetadata getAssemblyMetadata, Microsoft.Build.Shared.GetRegistrySubKeyNames getRegistrySubKeyNames, Microsoft.Build.Shared.GetRegistrySubKeyDefaultValue getRegistrySubKeyDefaultValue, Microsoft.Build.Tasks.GetLastWriteTime getLastWriteTime, Microsoft.Build.Tasks.GetAssemblyRuntimeVersion getRuntimeVersion, Microsoft.Build.Shared.OpenBaseKey openBaseKey, Microsoft.Build.Tasks.GetAssemblyPathInGac getAssemblyPathInGac, Microsoft.Build.Tasks.IsWinMDFile isWinMDFile, Microsoft.Build.Tasks.ReadMachineTypeFromPEHeader readMachineTypeFromPEHeader) [0x00578] in &lt;050f973d2a7f41969411264f5f4b2cfa&gt;:0 
    at Microsoft.Build.Tasks.ResolveAssemblyReference.Execute () [0x00000] in &lt;050f973d2a7f41969411264f5f4b2cfa&gt;:0 
    at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute () [0x00029] in &lt;7dd0c229019940a39d4282a335b99b6f&gt;:0 
    at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask (Microsoft.Build.BackEnd.ITaskExecutionHost taskExecutionHost, Microsoft.Build.BackEnd.Logging.TaskLoggingContext taskLoggingContext, Microsoft.Build.BackEnd.TaskHost taskHost, Microsoft.Build.BackEnd.ItemBucket bucket, Microsoft.Build.BackEnd.TaskExecutionMode howToExecuteTask) [0x001f6] in &lt;7dd0c229019940a39d4282a335b99b6f&gt;:0  [D:\wrkfldr\godot-project\BoomCraft.csproj]
  </code></pre>
  
  <p>Obviously <code>fusion.dll</code> cannot be found. I've found the dll file on the web but I have no idea where to put it, so Mono can see it. I tried referencing it in Visual Studio but it throws another error </p>
  
  <p><code>Please make sure it is a valid assembly or COM component</code></p>
  
  <p><a href="https://stackoverflow.com/questions/48057194/error-system-dllnotfoundexception-fusion-dll-on-azure-storage-using-visual-stud">This thread</a> is not related because it is strongly linked to Azure API, and I do not use that API in my project.</p>
  
  <p><strong>How can I trace back the location where Mono needs the file to be stored ?</strong></p>