I believe I'm doing everything right with my session so I'm not totally
sure why I'm getting this error.

I open a session , do a number of operations and once complete I call
SaveChanges - I am only calling SaveChanges once.

My concern is that perhaps this is an issue with my architecture: I have a
Windows Service that is consuming from a RabbitMQ Queue inside a class that
exists for the lifetime of the service.  When a message arrives it calls a
handler method which opens the session and saves stuff.

I declare a private DocumentStore at the top of that class - does this all
make sense - as there is only one instance of the class that runs the
DocumentStore there must be only one DocumentStore right?  Or should I be
ensuring it's a singleton somehow?

Thanks very much,
Pete

Windows Service -> instantiates an App instance in the OnStart of the
service.
App constructor calls docStore.Initialize(); on a private DocumentStore

RabbitMQ calls a hander method in App and this performs operations on the
class variable DocumentSTore

Is this all safe?

the only other possibility that is wrong is this - there are many petes
here:

petes.ForEach(session.Store);

                        foreach (var pete in petes)
                        {

session.Advanced.GetMetadataFor(opp)["Raven-Expiration-Date"] = new
RavenJValue(pete.Expires);
                        }

Where do you create the session and where do you call savechanges?

Can you provide some more information about the infrastructural code you
have around this?

I'm thinking this was actually around a Load NOT a Save -this was my
mistake sorry.  I was calling load too many times in a foreach so I have
changed to batch load and I hope this will solve all woes,
thansk
Pete