FieldList AccessViolationException

After months of running a service using RFA which hits the EZD service, I've run into a new issue that just popped up today. Every minute, I snapshot without update roughly 2600 RICs. After receiving a marketdata event, I attempt to decode a FieldList and get:

An exception of type 'System.AccessViolationException' occurred in RFA8_NET140_x64.dll but was not handled in user code
Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

private void DecodeFieldList(FieldList input)

{

if(null == input)return;

var it = new FieldListReadIterator();

it.Start(input); //Exception occurs here

..........

}

In a watch, all FieldList properties show "The metadata for 'RFA8_NET140_x64 is invalid. If you are debugging a minidump,etc...".

I have tracing turned on and I don't see anything that further explains what's happening. Happy to share the logs with a Reuters rep. Eventually after a stream of incoming messages from the box running the EZD app, I just get

<!-- Sending Ping to 'ezdBox:14002' on 'localhost' interface -->
<!-- Time: 10:53:47:597 -->

<!-- Ping Received from ezdBox:14002' on 'localhost' interface -->
<!-- Time: 10:53:57:598 -->

until I shut down.