absolument

@Gigeran Ok, i will try with ME interface (fluid & items) next time. But actually import bus + chest works extremely well too... I built from eight farms, and tested different designs, different sizes, at different frame rate... I can't reproduce this bug. It does not appear that depend on a particular design. Whatever the design, it does not work here, but it works perfectly elsewhere. I give up. I just hope it will working as expected when I would build this farm in my survival game.

On each way I manage mob essence did not affect the bug (drop by fluidduct, fluid import bus, or leave mob essence in the grinder...) I made 3 other mob farm on a fresh flat world : 7x7, 9x9 and 10x10 room and the problem did not occure. I will try again and reproduce a farm with 2 ME network, in another chunk and see what append.

In a creative map, I've build some mob-farming boxes, based on MFR Autospawner / Grinder, and ME network. But today, I find myself exposed to an incomprehensible problem : Grinders do not harvest all items. Only 3 or 4% of items are harvested, the rest remains on the floor. This is not my first attempt at mob-farm building, and I've never had this problem before. I even built another mob-farm almost identical to a neighboring chunk (on the same map), and it perfectly harvest all items. My design : box 10x6x10 (inner) 4 Grinder, 1 Autospawner 2 ME Network : 1 manage safari net (inject/remove to Autospawner), the other manage mob-essence and store the loot 1 Creative enregy cell All fit in the same chunk It's a flat world (redstone ready) There is a vanilla chest behind each grinders, which interfaces with the ME network. Except for harvesting items, everything works perfectly. Even so, I would have been wrong in the management of two ME networks, the items should still be harvested and stored in vanilla chests... I made all kinds of changes (height of grinder, energy/fluid connections, import/export bus, blocks...). Also, I try to restart the game/launcher, which finaly did not change anything I'm running out of ideas. Does anyone ever had to deal with grinders who botch their work in this way? I just noticed that there was an update of Technic plateform and launcher. It is that it took place between the two building (before the contruction of the farm that is malfunctioning, and after the other who works well). Does this update may be the cause?