Many organizations still find it painful to implement an enterprise resource planning (ERP) system. Although ERP projects are collaborative efforts that many separate organizations conduct, academic research has not investigated ERPs fully from this perspective. To identify the challenges in ERP development networks (EDNs), we carried out an interpretive empirical study by using grounded theory to analyze data. After identifying 10 EDN challenges and analyzing the associations between the challenges further, we constructed a model that explains the challenges in ERP development networks. Relationship conflicts (root causes) create or reinforce one or more operational problems (consequences). Changes in the EDN structure initiate or reinforce the other two types. Whereas the existing literature has discussed ERP challenges mainly separately, we offer a more profound explanation of how they emerge and interrelate. Our findings aid practitioners in recognizing and focusing on the root causes of challenges rather than firefighting consequences. The findings can provide useful insights into collaborative and dynamic environments where multiple organizations interact.