Contemporary Enterprise Resource Planning (ERP) system development is conducted in a multi-stakeholder network. It requires the collaboration of different organizations and stakeholders. Knowledge transfer (KT) is difficult and often causes failure in projects, yet it has not been thoroughly investigated from the network’s perspective. Thus, this interpretive case study investigates what makes KT difficult in ERP development networks. As a result, seven categories of KT challenges were found: articulating domain knowledge, unwillingness to communicate, excessive trust, using informal communication channels and methods, different ways of working, missing or unidirectional connections between parties, and unsuitable or missing tools. The main contribution is gaining a deeper understanding of ERP development networks and especially about what makes KT difficult when developing ERP systems in a multistakeholder context. These findings imply that a shared development model for the EDN needs to be created in order to avoid KT challenges.