Open Government Data is an initiative that promotes transparency, accountability and value creation by making government data available to all. Open government data initiatives have become very popular worldwide because of the benefits that they can entail, especially in developed countries. However, many of these initiatives no always achieve the expected benefits. Although related research has reported that most of these initiatives face various problems affecting their success, little emphasis has been put on understanding such problems. Accordingly, in this study, we report our efforts to explore the main problems affecting open government data initiatives. Specifically, we performed a literature review to identify six problem categories, its subcategories, and its incidence. Additionally, using an Information Systems adoption process, we established the impact and occurrence of each of these problems before, during, and after an open government data initiative.