Fix StackOverflowException when serializing complex exceptions#3305
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Fix StackOverflowException when serializing complex exceptions#3305
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Modified ErrorSerializerSettingsFactory to only serialize safe, well-known exception properties (Message, StackTrace, Source, HelpLink, HResult, Data, InnerException). This prevents serialization of complex properties from derived exception types like CsvHelper.FieldValidationException that can cause infinite recursion and StackOverflowException during JSON serialization. Also added MaxDepth=64 as an additional safety measure. Fixes #550 Co-authored-by: YunchuWang <12449837+YunchuWang@users.noreply.github.com>
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Extracted CreateThrownException helper method to reduce code duplication in ErrorSerializerSettingsFactoryTests. Co-authored-by: YunchuWang <12449837+YunchuWang@users.noreply.github.com>
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[WIP] Fix CsvHelper FieldValidationException and StackOverflowException
Fix StackOverflowException when serializing complex exceptions
Jan 5, 2026
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Summary
What changed?
ErrorSerializerSettingsFactory.ExceptionResolverto use an allowlist approach for exception property serializationMessage,StackTrace,Source,HelpLink,HResult,Data,InnerExceptionMaxDepth=64as an additional safety measureWhy is this change needed?
Exceptions with complex/deeply nested properties (e.g., CsvHelper's
FieldValidationExceptioncontainingReadingContextwith the entire CSV reader state) cause infinite recursion during JSON serialization.ReferenceLoopHandling.Ignoreonly handles true circular references (same object instance), not deep object graphs.StackOverflowExceptioncannot be caught, crashing the process.Issues / work items
Project checklist
WebJobs.Extensions.DurableTaskpackageEventSourcelogsv2.xbranchAI-assisted code disclosure (required)
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ErrorSerializerSettingsFactory.cs,ErrorSerializerSettingsFactoryTests.csAI verification (required if AI was used):
Testing
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ErrorSerializerSettingsFactoryTests)Manual validation (only if runtime/behavior changed)
Notes for reviewers
System.Exceptionproperties needed for debugging/diagnostics.Warning
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Original prompt
This section details on the original issue you should resolve
<issue_title>CsvHelper FieldValidationException & Orchestrator throws StackOverflowException</issue_title>
<issue_description>I'm parsing a csv file with CsvHelper with bad data in it.
I have a StackOverflowException
You have a simple project attached to reproduce the issue.
soe.zip
</issue_description>
<agent_instructions>check if this issue still exists, if so fix it</agent_instructions>
Comments on the Issue (you are @copilot in this section)
@cgillum Thanks for this report and for the reference project. I was able to reproduce the issue. It looks like a bug in our exception serialization code. @cgillum The problem is `FieldValidationException`. It's a complex data structure and the Json.NET serializer we use runs into a `StackOverflowExcepti...💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.