This error seems to be happening with a couple of mods (Calculator and Mekanism - not sure of any others).
The console spam looks like this:
Code
Mekanism Example:
[02:13:45] [ic2-poolthread-27/WARN] [ic2.EnergyNet]: Tile mekanism.generators.common.tile.TileEntityAdvancedSolarGenerator@5d060580 (dim 0: 522/78/39) removal without registration
Calculator Example:
[21:06:20] [ic2-poolthread-1/WARN] [IC2.EnergyNet]: Tile sonar.calculator.mod.common.tileentity.machines.TileEntityBasicGreenhouse@6506fb62 (dim 0: -226/64/-250) removal without registration
Errors are currently happening with CurseForge Release: industrialcraft-2-2.8.16-ex112
Also tested with beta build: industrialcraft-2-2.8.35-ex112.jar
This issue has also been reported on their issue trackers it seems (more than once)