Post SP2019 Sep CU webpart problem

Question

Hi,

After installing the SharePoint 2019 September 10th Cumulative Update (this one), our custom webpart toolbar property appears to be causing an issue when attempting to render the webpart control. The exception we encounter is the following:

[ArgumentException: The serialized data is invalid.]
  at Microsoft.SharePoint.WebPartPages.SPObjectStateFormatter.Deserialize(Stream inputStream)
  at Microsoft.SharePoint.WebPartPages.Utility.DeserializeByteArrayToObject(SPSerializationBinderBase binder, Byte[] bytes)
  at Microsoft.SharePoint.WebPartPages.BinaryWebPartDeserializer.LoadInitialWebPart()
  at Microsoft.SharePoint.WebPartPages.BinaryWebPartDeserializer.Deserialize()
  at Microsoft.SharePoint.WebPartPages.SPWebPartManager.CreateWebPartsFromRowSetData(Boolean onlyInitializeClosedWebParts)

[UnsafeControlException: The control type 'System.Collections.Generic.List`1[[IC.He.SharePointWeb.SP.WebParts.WebpartColumn, IC.He.SharePointWeb, Version=1.0.0.0, Culture=neutral, PublicKeyToken=50a0670ec03a0037]]' is not allowed on this page. ]
  at Microsoft.SharePoint.WebPartPages.SPSerializationBinder.IsAllowedType(Type type)
  at Microsoft.SharePoint.WebPartPages.SPSerializationBinderBase.CheckIfAllowedType(Type type)
  at Microsoft.SharePoint.WebPartPages.SPSerializationBinderBase.BindToType(String assemblyName, String typeName)
  at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Bind(String assemblyString, String typeString)
  at System.Runtime.Serialization.Formatters.Binary.ObjectReader.GetType(BinaryAssemblyInfo assemblyInfo, String name)
  at System.Runtime.Serialization.Formatters.Binary.ObjectMap..ctor(String objectName, String[] memberNames, BinaryTypeEnum[] binaryTypeEnumA, Object[] typeInformationA, Int32[] memberAssemIds, ObjectReader objectReader, Int32 objectId, BinaryAssemblyInfo assemblyInfo, SizedArray assemIdToAssemblyTable)
  at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadObjectWithMapTyped(BinaryObjectWithMapTyped record)
  at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run()
  at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
  at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
  at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream)
  at Microsoft.SharePoint.WebPartPages.SPObjectStateFormatter.DeserializeValue(SerializerBinaryReader reader)
  at Microsoft.SharePoint.WebPartPages.SPObjectStateFormatter.DeserializeValue(SerializerBinaryReader reader)
  at Microsoft.SharePoint.WebPartPages.SPObjectStateFormatter.Deserialize(Stream inputStream)

In our web.config we have defined our assembly as a safe control in the following manner:

      <SafeControl Assembly="IC.He.SharePointWeb, Version=1.0.0.0, Culture=neutral, PublicKeyToken=50a0670ec03a0037" Namespace="IC.He.SharePointWeb.SP.WebParts" TypeName="*" Safe="True" />
      <SafeControl Assembly="IC.He.SharePointWeb, Version=1.0.0.0, Culture=neutral, PublicKeyToken=50a0670ec03a0037" Namespace="IC.He.SharePointWeb.WebParts" TypeName="*" Safe="True" />

I have tried tinkering with the AllowListItems, since it seems to be related to the serialization of collections, but I couldn't find a value that corresponds to the Sytem.Collections.Generic.List type.

I attach the full correlation log too.

Any help would be appreciated

Answer 1

Hi @Pete Marone ,

The error message indicates that the serialized data is invalid, and the control type System.Collections.Generic.List1[[IC.He.SharePointWeb.SP.WebParts.WebpartColumn, IC.He.SharePointWeb, Version=1.0.0.0, Culture=neutral, PublicKeyToken=50a0670ec03a0037]]` is not allowed on the page.

Try to install the SharePoint Server 2019 Language Pack Update (KB5002597) to see if the issue is resolved.

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Answer 2

Hi @Pete Marone ,

Too bad it didn't solve your problem. I couldn't find some information on this issue. If you think that this matter does not affect you much, perhaps you can wait for the next update as it may be this update that is causing the problem. We sincerely recommend you go to SharePoint Feedback community to provide your feedback: SharePoint · Community (microsoft.com).

If it is seriously affecting your business, please go to the website Global Customer Service phone numbers - Microsoft Support) to find related number and call it to create a new Phone Service Request to Microsoft Phone Support team.

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