The emergence of platforms is shifting the locus of digital innovation to ecosystems on which numerous developers create extensions with additional functionalities. Despite all the potential benefits for complementors, however, this new organizing logic of digital innovation also introduced essential new risks. Recent studies in IS focused on risk of IT projects from a contingency perspective neglecting the complexity of ecosystems. In order to shed light on this, our work examines how app architecture as a complementor´s control mechanism and four types of ecosystem hazards shape the likelihood and impact of the risk of failure in thirdparty innovation. By using a configurational approach based on fuzzy-set qualitative comparative analysis (FsQCA), we display complex interactional effects of the causal conditions on complementors’ perception of hazardous environments and thus provide valuable insights for both practice and theory on platform ecosystems.