Prefabs on play

Hi guys! I'm doing a game on which the AI is in charge of deciding when to build bases out of a unit, when to build units out of a base, to do nothing etc. I have all my objects set to public on my scripts and on the inspector I assigned the required prefabs to the correspondent field. That was ok and working at the beginning, now the game started to trigger bugs on the prefabs, every time I hit play I have error messages, while I was checking what was going on I noticed that the prefab attached on the inspector disappears when I hit play. Does anybody know what is going on?