Despite the importance and prevalence of structures (or records) in programming, no study till now has deeply analyzed the bugs made in their usage. This paper makes a first step to fill that gap by systematically and deeply analyzing a subset of structure usage bugs. The subset, referred to as MSFH bugs, are errors of omission associated with structure fields when they are handled in a grouped context. We analyze the nature of these bugs by providing a taxonomy, root cause analysis, and barrier analysis. The analysis provided many new insights, which suggested new solutions for preventing and detecting the MSFH bugs.