What does Windows error code 689 (ERROR_DBG_REPLY_LATER) mean?

ERROR_DBG_REPLY_LATER

What ERROR_DBG_REPLY_LATER means

A debugger has deferred its reply for the current debug event. In practical terms, this status belongs to asynchronous debugger control: the debugger postpones continuation while another operation, user decision, or inspection step is pending.

Typical causes

• The debugger is waiting for symbol loading or a user command
• A remote debugging transport has not completed the requested inspection
• The event is intentionally parked so another thread or process can be examined

How to investigate

1. Identify the outstanding debug event and the thread that owns it
2. Check whether the debugger UI, extension, or remote transport is waiting for input
3. Verify that every deferred event has a bounded completion or cancellation path

Developer guidance

Do not convert a deferred reply into an immediate retry loop. The event remains owned by the debugger until it explicitly resumes or terminates the target.

References

• Microsoft: System error codes 500–999