java.lang.AbstractMethodError: crazypants.enderio.conduit.TileConduitBundle.receiveGas(Lnet/minecraftforge/common/util/ForgeDirection;Lmekanism/api/gas/GasStack;Z)I
at mekanism.common.tile.TileEntityGasTank.onUpdate(TileEntityGasTank.java:84)
at mekanism.common.tile.TileEntityBasicBlock.func_145845_h(TileEntityBasicBlock.java:73)
at net.minecraft.world.World.func_72939_s(World.java:1939)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:186)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Stacktrace:
at mekanism.common.tile.TileEntityGasTank.onUpdate(TileEntityGasTank.java:84)
at mekanism.common.tile.TileEntityBasicBlock.func_145845_h(TileEntityBasicBlock.java:73)

Using version 542 dev

also dev 543 still same issue.

Due to an outdated API. @tterrag1098 already has this fixed in development.