c# - XmlSerializer giving FileNotFoundException at constructor

Question

An application I've been working with is failing when I try to serialize types.

A statement like

XmlSerializer lizer = new XmlSerializer(typeof(MyType));

produces:

System.IO.FileNotFoundException occurred
  Message="Could not load file or assembly '[Containing Assembly of MyType].XmlSerializers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified."
  Source="mscorlib"
  FileName="[Containing Assembly of MyType].XmlSerializers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
  FusionLog=""
  StackTrace:
       at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
       at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)

I don't define any special serializers for my class.

How can I fix this problem?

Answer 1

Believe it or not, this is normal behaviour. An exception is thrown but handled by the XmlSerializer, so if you just ignore it everything should continue on fine.

I have found this very annoying, and there have been many complaints about this if you search around a bit, but from what I've read Microsoft don't plan on doing anything about it.

You can avoid getting Exception popups all the time while debugging if you switch off first chance exceptions for that specific exception. In Visual Studio, go to Debug -> Exceptions (or press Ctrl + Alt + E), Common Language Runtime Exceptions -> System.IO -> System.IO.FileNotFoundException.

You can find information about another way around it in the blog post C# XmlSerializer FileNotFound exception (which discusses Chris Sells' tool XmlSerializerPreCompiler).