Update: I restarted the upgrade and followed the sequence below and was able to make it work until I upgraded CMS but as soon as I upgraded Commerce, it started throwing error. So the issue is not with EPiserver Framework version but Commerce version.

• Upgrade EPiServer Find related packages - No issue
• Upgrade TinyMce and EPiServer Forms - No issue
• Upgrade EPiServer ServiceAPI and ImageSharp - No issue
• Upgrade EPiServer and AspnetCore packages from 12.21.7 to 12.22.0 - No issue
• Upgrade Commerce.UI+Personalization.Commerce+Tracking.Commerce from 14.23 to 14.28 - No issue
• Upgrade Commerce 14.28.0 to 14.29.0 = Failed with above error

Thanks for the report. We are aware Commerce has an old dependency to BinaryFormatter. We know how to remove the dependency but it is some work, especially doing it without breaking changes. I have brought this up for prioritization again, but for now Commerce can only run on .NET 8.

Thanks @Magnus. 

After failing to make it work with 14.29.0 I tested following two scenarios. Sharing in case someone else encounters and it may help them.

• If you upgrade from 14.29.0 to 14.30.0 the solution loads without any error.
• If you upgrade directly from older version of Commerce to 14.30.0, it fails to load the site with expected BinaryFormatter error. 

Conclusion: We will use .NET 8 for the time being. 

I noticed too that I sometimes got an error already in startup, in another project I didn't. But you will get an error as soon as you publish a product update (or price update etc). So it is not currently usable on .NET 9.

There is an official compatibility package available on NuGet: https://www.nuget.org/packages/System.Runtime.Serialization.Formatters

It enabled us to use CMS 12 with .NET 9. But it's great to hear that Optimizely is working on replacing BinaryFormatter with something modern and more secure!

Oh, really? Surprised it works as a drop-in replacement without any changes to our code. Thanks for the tip!

We're going to rip it out anyway I think, it isn't actually needed for anything, it is a legacy to send remote events from the time when there was a separate Content Manager application. We can solve the same thing using regular in-process events now.

Hi

Has anyone tested with placing an order? I received "Type provided must be an Enum" exception from calling OrderRepository Save method

  System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
       ---> System.ArgumentException: Type provided must be an Enum.
         at System.ComponentModel.EnumConverter..ctor(Type type)
         at Mediachase.Commerce.Shared.ResourceEnumConverter..ctor(Type type)
         at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
         at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
         --- End of inner exception stack trace ---
         at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)
         at System.Reflection.MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
         at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
         at System.Reflection.ConstructorInfo.Invoke(Object[] parameters)
         at System.ComponentModel.ReflectTypeDescriptionProvider.CreateInstance(Type objectType, Type callingType)
         at System.ComponentModel.ReflectTypeDescriptionProvider.ReflectedTypeData.GetConverter(Object instance, Boolean verifyIsRegisteredType)
         at System.ComponentModel.TypeDescriptor.DefaultTypeDescriptor.GetConverter()
         at System.ComponentModel.TypeDescriptor.GetConverter(Type type)
         at Newtonsoft.Json.Serialization.JsonTypeReflector.CanTypeDescriptorConvertString(Type type, TypeConverter& typeConverter)
         at Newtonsoft.Json.Serialization.DefaultContractResolver.CanConvertToString(Type type)
         at Newtonsoft.Json.Serialization.DefaultContractResolver.CreateContract(Type objectType)
         at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
         at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
         at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
         at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
         at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)
         at Newtonsoft.Json.JsonConvert.SerializeObjectInternal(Object value, Type type, JsonSerializer jsonSerializer)
         at EPiServer.Commerce.Order.Internal.DataAccess.SerializableCartDB.Save(SerializableCart cart)
         at EPiServer.Commerce.Order.Internal.SerializableCartProvider.Save(ICart cart)
         at EPiServer.Commerce.Order.Internal.DefaultOrderRepository.Save(IOrderGroup order)