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As an intiator, I can send custom requests for market updates (35=U) and receive Execution Reports for existing orders sent by another user. However, as soon as I try and send a NewOrderSingle, I enter into a loop where the server returns a ResendRequest, I send SequenceReset and another NewOrderSingle to which I get another ResendRequest etc. I have set ValidateSequenceNumbers=N.
Have spent a couple of days trying to work out what's going on. Would greatly appreciate any help.