Spamming in the log... Possibly causing Lag (Unable to go on server)

[Rongmario]

Hello there, I am running a custom pack created by myself - I have a question, since yesterday my server have been spamming this error:

17.03 11:41:28 [Server] WARNING EnergyNet.removeTileEntity: mods.railcraft.common.blocks.machine.alpha.TileSteamTurbine@1104c143 (mods.railcraft.common.plugins.ic2.TileIC2MultiEmitterDelegate@44fadd40) wasn't found (added), skipping

Running on Windows, this is a dedi-server by ApolloCoServers using Multicraft control panel.
This has been spamming in these 2 days causing intense lag, getting errors that kick you out of the server, ping is still fabulous so its something within the world..

 

[Spacetime Mogul]

I don't have a solution.
But since nobody else has answered you yet, I might as well point out some details that may or may not be apparent to you.
Based on the line you showed, it seems to be two mods that are involved - Railcraft and Industrial Craft 2. The object in the game that the problem is related to seems to be a railcraft steam turbine, which would make sense as it produces IC2's energy units.

IC2 has changed the way that it handles electricity in the last months, and since it has gone "experimental", the way that other mods can interact with IC2 (IC2's API) may have changed several times. As a wild guess - it could be that you either have a railcraft version installed that has problems with your IC2 installation, or that another mod is likewise incompatible with the IC2 version you use.

It is practically impossible to give you any good advice though if you don't post a complete crash-log or, in the case that there is none, at least give the exact versions of minecraft (the one on your server) and the mods you installed. The fact that you haven't given that information may well be a reason why nobody else has answered you yet.