Your Birdsnest fern looks like one I used to have a few years back,
Bird's Nest Fern (Asplenium antiquum 'Crissie') and it appears to have been watered in the center of the rosette which (in my experience) is not a good idea because when water sits in that center, it will cause rot. As Daisy suggested, use an airy, well draining potting medium and always water beneath the leaves, atop the soil. When mine was outside, I'd spray it with the garden hose but I would always tip it afterwards to allow any water in the rosette to drain away.
