A strange error occured recently on our BizTalk. It suddenly showed up in the EventLog and the Orchestration got suspended.
"Index was outside the bounds of the array" happened at the Receive shape connected to a Request-Response-Port where we called a WebService.
It had worked properly a day before.
The response message from the service we called was not very large and the data seemed ok.
The error came from here:
Void Write[our type]ToXml(System.Runtime.Serialization.XmlWriterDelegator, System.Object, System.Runtime.Serialization.XmlObjectSerializerWriteContext, System.Runtime.Serialization.CollectionDataContract).
From within BTS/WCF Messaging.
The error was reproducible.
As it turned out that BizTalk was throttling (State 4 : Memory Pressure)! Obviously it was not able to create the array in memory.
I never had this error before. So: lesson learned. :-)
After restarting the HostInstances, everything worked fine again.