FIX Error Codes – Knowledge Base
This knowledge base provides detailed explanations for common FIX protocol errors, reject codes, and troubleshooting steps. Each error page includes what the error means, why it happens, example log snippets, and how to fix it.
Reject 5: Incorrect value
SessionRejectReason 5 (Invalid tag number) indicates that a tag number in the message is not recognized or is invalid fo...
Tag 371: Tag missing
Tag 371 (RefTagID) in a FIX Reject message indicates that the original message was rejected because a specific tag was m...
BusinessMessageRejected: Business message rejected (j)
BusinessMessageRejected (MsgType=j) is an application-layer reject message sent when a business-level message (like NewO...
SessionDisconnect: Session disconnected
A session disconnect occurs when the FIX session is terminated unexpectedly. This can happen due to network issues, appl...
InvalidMsgType: Invalid message type
An invalid MsgType error occurs when tag 35 (MsgType) contains a value that is not recognized in the FIX specification o...
Reject 6: Required tag missing
SessionRejectReason 6 indicates that a mandatory tag required by the FIX specification or business rules is missing from...
Reject 102: Too late to cancel
Reject code 102 (CxlRejReason) indicates that an OrderCancelRequest arrived too late. The order has already been filled,...
Reject 103: Invalid price
Reject code 103 (OrdRejReason) indicates the price provided in the order is invalid. This can mean the price is outside ...
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