WCF Troubleshooting

This error usually means the client cannot locate the service address or the binding configuration is mismatched.

System.ServiceModel.EndpointNotFoundException:
  Could not find a suitable endpoint element with name '' and contract 'IMyService' in the ServiceModel client configuration section.

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Remedies

1. Verify the service address in app.config or web.config.
2. Ensure the binding types match on both client and server.
3. Check that the service is running and the endpoint is reachable (e.g., via curl).

Security misconfiguration often leads to this exception.

System.ServiceModel.Security.SecurityNegotiationException:
  The remote party sent a message that could not be understood.

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Checklists

• Both client and service must use the same SecurityMode.
• If using certificates, ensure they are installed in the correct store and have proper permissions.
• Validate the clock synchronization between machines.

DataContract mismatches cause serialization failures.

System.Runtime.Serialization.SerializationException:
  There was an error deserializing the object of type 'MyNamespace.MyType'.

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Solutions

• Make sure [DataContract] and [DataMember] attributes are applied consistently.
• Check for versioning issues – added/removed members require EmitDefaultValue handling.
• Ensure collections implement IEnumerable and are serializable.

Common performance pitfalls and mitigation strategies.

Typical Causes

• Large messages without streaming.
• Excessive use of ReliableSession.
• Improper throttling settings.

Recommendations

1. Enable TransferMode.Streamed for large payloads.
2. Adjust ServiceThrottlingBehavior (maxConcurrentCalls, maxConcurrentSessions).
3. Profile using SvcTraceViewer and Windows Performance Monitor.