There are some issues that may arise:

Irrigation

The vermicomposter needs to be watered rarely or never, since the fresh remains of the vermicomposter have a high % of humidity. Furthermore, because its closed structure, the vermicomposters well preserve the indoor humidity, creating the ideal microclimate for the development of red worms.

However, if the remains which are deposited in the vermicomposter do not contain enough water and there is a certain dryness, a little water should be sprinkled, better if sprayed and always openning the tap and a bucket ready to collect the liquid fertilizer.

Mold

The mold is good for the process, because the fungi are part of the worms feeding. In fact, Eisenia sp. can not feed directly from the waste that we provide but from the decomposing microorganisms of this organic matter.

When will be the first harvest?

Depends on many factors: earthworms population, humidity, temperature and type of food. It is very normal to have to wait several months the first time, because earthworm population is not large enough. Thus, it can take 6 months to a year to collect the first tray of worm compost. When the urban composter is in its full process, you can pick a tray every two months and a lot of liquid fertilizer.