Issue description:

What happens:

java.lang.ClassCastException: net.minecraftforge.fluids.capability.FluidTankPropertiesWrapper cannot be cast to net.minecraftforge.fluids.capability.IFluidHandler
at com.raoulvdberge.refinedstorage.RSUtils.getFluidHandler(RSUtils.java:241)
at com.raoulvdberge.refinedstorage.tile.TileImporter.updateNode(TileImporter.java:92)
at com.raoulvdberge.refinedstorage.tile.TileNode.func_73660_a(TileNode.java:79)
at net.minecraft.world.World.func_72939_s(World.java:1804)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:620)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:709)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:613)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:149)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:471)
at java.lang.Thread.run(Thread.java:745)

What you expected to happen:

Steps to reproduce:

1. Load my world

...

Version (Make sure you are on the latest version before reporting):

• Minecraft: 1.10.2
• Forge: 12.18.3.2202
• Refined Storage: 1.2.18

Does this issue occur on a server? [yes/no]
No

If a (crash)log is relevant for this issue, link it here:

[pastebin/gist/etc link here]
https://gist.github.com/Tntdruid/f981cd1185b06e648717cb2cded1e32a

You stuck an importer on a fluid tank, which fluid tank would that be? It's causing an issue when getting the tank, most likely not an RS fault.

Yep, the tank is returning a IFluidTankProperties on a tile.getCapability(CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY, side) call.

@Tntdruid nothing changed to that code in like for ever. What tank was giving the issue? Did you update any other mods in the mean while?

@way2muchnoise its on Electrolytic Separato from Mekanism, never had that crash before 1.2.18

Downgrade to Refined Storage: 1.2.17 and the world load again :)

we got the same here SleepyTrousers/EnderIO-1.5-1.12#4009 --- so that's not on RS's side...