You are testing the latest version of an air-traffic control system prior to production deployment...

The critical information missing from the defect report is a detailed description of the defect to enable reproduction. A clear and concise description of the steps taken to reproduce the defect is essential for developers to understand the context and to be able to replicate the issue in their environment. Without this information, it can be challenging to diagnose and fix the defect. The ISTQB CTFL syllabus emphasizes the importance of providing all necessary details in a defect report to facilitate effective communication and resolution.

References:ISTQB CTFL Syllabus, Section 5.5, "Defect Management."