Error/Information when saving Server

Hello everybody

First of all im running the Rustserver on Windows Server 2012 R2

Everytime my server autosaves or when I save, it displays a yellow message above the normal saving dialog:

Entity is NULL but is still in saveList - not destroyed properly? assets/bundled/prefabs/oilfireballsmall.prefab[80592] <- yellow
Saved 37,887 ents, serialization(0.00), write(0.01), disk(0.00) totalstall(0.01). <- saving dialog

thx for the help