All the things I have tried:
Standard medium I use is 40-45% coconut coir, 40-45% peat and 5-10% worm castings. All soaked and well wetted before using.
High light in form of T8 6500K 2 foot light dual bulb. Medium light in a dome lamp with a 6500K 80 watt eq. compact fluorescent. All lights withing 12 inches of moss.
Closed terrarium, closed terrarium with small vents, open terrarium with pond for humidity.

All the mosses I have tried do the same thing, they dry out and die. I have tried at least 5 varieties in at least 3 different setups each with the same results.

The small piece that has survived for now has been soaked and removed from the medium light. I have slim hope it will survive but there is still hope. I soak the medium to saturation with water standing in the bottom catch tray and keep it that way. We will see if I have found the way I can finally grow moss or not, if it survives.