Add newtonsoft
MODIFY
WalletWasabi.Backend/Startup.cs
WalletWasabi.Backend/Startup.cs
@@ -34,6 +34,12 @@ namespace WalletWasabi.Backend
services.AddMvc(options => options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(BitcoinAddress))))
.AddControllersAsServices();
+ services.AddMvc()
+ .AddNewtonsoftJson();
+
+ services.AddControllers()
+ .AddNewtonsoftJson();
+
// Register the Swagger generator, defining one or more Swagger documents
services.AddSwaggerGen(c =>
{

MODIFY
WalletWasabi/WalletWasabi.csproj
WalletWasabi/WalletWasabi.csproj
</PropertyGroup>
<ItemGroup>
+ <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0" />
<PackageReference Include="NBitcoin" Version="5.0.0" />
<PackageReference Include="Microsoft.Win32.Registry" Version="4.6.0" />
</ItemGroup>

Add newtonsoft https://docs.microsoft.com/en-us/aspnet/core/migration/22-to-30?view=aspnetcore-3.0&tabs=visual-studio#jsonnet-support