I've been trying out after effects, lovely editor.
However, after a while everything I tried rendering appears black, but the audio works. Adobe Media Encoder also does the same thing. The "video output" function is checked. The preview fully works.
Does anyone know what this could be? Thanks!
Nobody can tell you anything without proper system info or other technical details, including a better explanation of what you are actually doing, render settings, footage used and whatnot.
The most likely problem is that you are not using one of the presets for rendering or that you are not using the active camera in your composition panel. The only view that renders is Active Camera. If ont of those is not the problem then we need a detailed description of your workflow.