When you are in the course environment, it can sometimes happen that certain components are not visible. This might mean that I have temporarily taken a component offline (to make adjustments) or that there is a ‘cache’ issue. In the first case, the component will usually be available again within a day. If it’s a cache problem, you will generally see multiple components not working. Try restarting your web browser, clearing your browser cache, and/or restarting your computer. If the issue persists, feel free to send me a message.