It's fine, but it is a sign that your compost pile is staying too wet/ not draining well enough/ not aerated enough.
They always say a compost pile should be as damp as a wrung out sponge. Too dry and it stops working (until the rain comes, when it will start up again). Too wet and it excludes air, which is needed for the composting process.
So I would stir everything up, fluff it up, and then make sure you have enough channels for the movement of air and water.
A bigger pile works better. Compost everything!!!