Objective: The purpose of this paper is to identify the largest cognitive challenges faced by novices developing software in teams. Method: Using grounded theory, we conducted an ethnographic study for two months following four ten person novice teams, consisting of computer science students, developing software systems. Result: This paper identifies version control and merge operations as the largest challenge faced by the novices. The literature studies reveal that little research appears to have been carried out in the area of version control from a user perspective. Limitations: A qualitative study on students is not applicable in all contexts, but the result is credible and grounded in data and substantiated by extant literature. Conclusion: We conclude that our findings motivate further research on cognitive perspectives to guide improvement of software engineering and its tools.