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Azure Functions (Isolated Worker) Upgrade Version 4 to 5

This is part of the NServiceBus Upgrade Guide from Version 8 to 9, which also includes the following individual upgrade guides for specific components:

Transports
Hosting
Other

Default serializer has changed

The default serializer has changed from Json.NET to System.Text.Json.

The Json.NET serializer can continue to be used by adding a package reference to the NServiceBus.Newtonsoft.Json package and setting NewtonsoftJsonSerializer as the serializer:

var host = new HostBuilder()
.ConfigureFunctionsWorkerDefaults()
.UseNServiceBus(configuration =>
{
    configuration.AdvancedConfiguration.UseSerialization<NewtonsoftJsonSerializer>();
})
.Build();

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