ForgeEssentials Version: 1.7.10-1.4.6.1348-server
Forge Version: 1.7.10-10.13.4.1558-1.7.10-universal
Mekanism Version: 1.7.10-9.1.0.281
Minecraft Version: 1.7.10

ForgeEssentials can't pick up interaction events to Mekanism blocks. I created an area, and gave permission to my members group to interact with the Mekanism blocks. I gave the following permissions:

"fe.protection.interact.Mekanism.MachineBlock2.4": "true", "fe.protection.use.minecraft.baked_potato": "true", "fe.protection.interact.Mekanism.MachineBlock.5": "true", "fe.protection.interact.Mekanism.EnergyCube": "true", "fe.protection.interact.Mekanism.MachineBlock.6": "true", "fe.protection.interact.Mekanism.MachineBlock.13": "true", "fe.protection.interact.Mekanism.MachineBlock.15": "true", "fe.protection.interact.BiblioCraft.BiblioFancySign.*": "false", "fe.protection.interact.MekanismGenerators.Generator.6": "true", "fe.protection.interact.Mekanism.EnergyCube.*": "true"

Then just to be safe, i saved them and stopped and started the server and connected with my members group player. I was unable to interact with any of the Mekanism blocks (factories, chests, etc.).

To confirm that this is actually the case (that there's an incompatibility), i then added the wooden door interaction permission:

"fe.protection.interact.minecraft.wooden_door.*": "true",

Then i saved, stopped and started the server again (as im doing these edits through config files). With my member account i was able to open and close the wooden door, but still unable to interact with the Mekanism blocks.

P.S. For the member account tests, i did them myself instead of relying on another player so my observations are not error prone.

P.P.S. Mekanism blocks set to public or private still suffer from this problem.

Try using these ingame commands instead:

/p group members allow fe.protection.interact.Mekanism.MachineBlock.*
/p group members allow fe.protection.interact.Mekanism.MachineBlock2.*
/p group members allow fe.protection.interact.Mekanism.MachineBlock3.*
/p group members allow fe.protection.interact.Mekanism.EnergyCube.*
/p group members allow fe.protection.interact.MekanismGenerators.Generator.*

Aha! I figured it out!

It was server.properties spawn-protection that was messing it up. Setting that variable to 0 fixed it. Sorry for any wasted time.

No problem. Great you found the culprit.

I already tried those yesterday when i saw that the specific ones weren't working. Those dont work either :/