The studies in educational settings have generated a significant body of knowledge on the conditions that facilitate productive peer collaboration, promoting learning outcomes and efficient problem-solving. Despite frequent warnings, such as those by Howe and Mercer (Children’s social development, peer interaction and classroom learning (primary review research survey 2/1b, 2007), that peer dialogue often lacks productivity, researchers have focused more on successful interaction cases. Given that unsuccessful peer collaboration remains understudied, and considering the various reasons it may fall short, this chapter examines the barriers preventing efficient collaborative problem-solving in the school context. It aims to identify and categorize these key challenges among adolescents, whose developmental achievements should equip them with the cognitive and social skills necessary for constructive problem-solving dialogue. Our analysis draws on findings from the recent systematic review (Baucal et al., Educational Research Review, 41, 100567, 2023) and is further informed by newer studies published later, contributing to a deeper understanding of the factors hindering students' collaboration, linking these factors with the phases of problem-solving, and offering recommendations for scaffolding by teachers.