Looks like you are missing server target for your project. Did you create YourProjectNameServer.Target.cs build file? In YourProjectFolder/Source folder you will have YourProjectName.Target.cs file. In addition to this, you will need YourProjectNameServer.Target.cs file. You can use the below code but make sure to change YourProjectName to your actual project name:
using UnrealBuildTool;
using System.Collections.Generic;
public class YourProjectNameServerTarget : TargetRules
{
public YourProjectNameServerTarget(TargetInfo Target)
{
Type = TargetType.Server;
bUsesSlate = false;
UEBuildConfiguration.bUseLoggingInShipping = true; // If you want logging in shipping build
}
//
// TargetRules interface.
//
public override void SetupBinaries(
TargetInfo Target,
ref List<UEBuildBinaryConfiguration> OutBuildBinaryConfigurations,
ref List<string> OutExtraModuleNames
)
{
OutExtraModuleNames.AddRange( new string] { "YourProjectName" } );
}
// Obsolete from 4.15+
public override bool GetSupportedPlatforms(ref List<UnrealTargetPlatform> OutPlatforms)
{
// It is valid for only server platforms
return UnrealBuildTool.UnrealBuildTool.GetAllServerPlatforms(ref OutPlatforms, false);
}
}
See this documentation for more information: https://docs.unrealengine.com/latest/INT/Programming/UnrealBuildSystem/TargetFiles/