Particle size can be too small. For example, sawdust sized and wet materials can decrease aeration, reduce the rate of composting and perhaps cause anaerobic conditions leading to odor problems. What's important is to understand how greens and browns affect the compost process and to use them to manage your compost system. N ratio of your materials by using the chart below. If you have a slow connect speed, the Virtual Pile may take a minute or two to load.
Wood chips are very high in carbon, but low in nitrogen.
All plant material contains a mixture of Carbon and Nitrogen, and all plant material will compost over time. You will find the right mix of materials for your composting needs by trial and error. N ratio, just understand that it can be a factor in your composting process.