Missing Mods:
Forge : [12.18.1.2039,)

net.minecraftforge.fml.common.MissingModsException: Mod BiomesOPlenty (Biomes O' Plenty) requires [Forge@[12.18.1.2039,)]
at net.minecraftforge.fml.common.Loader.sortModList(Loader.java:274)
at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:525)
at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:97)
at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:328)
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:121)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:431)
at java.lang.Thread.run(Thread.java:745)

• Biomes O' Plenty: BiomesOPlenty-1.10.2-5.0.0.2155-universal.jar
• Minecraft: 1.10.2
• Forge: 12.18.3.2239

BoP 5.0.0.2155 loads fine with Forge 12.18.3.2239, you should double-check your setup.

Can confirm, BoP loads just fine with Forge 12.18.3.2239.

Crash report is from Creeperhost server side log.

I said server not client!!!!
The issue lies with the server side end. Client loads up fine the error is coming from the server side.

crash-2017-03-05_18.00.30-server.txt

FML: MCP 9.32 Powered by Forge 12.18.1.2016 127 mods loaded, 127 mods active
U FML{8.0.99.99} [Forge Mod Loader] (forge-1.10.2-12.18.1.2016-failtests-universal.jarx)
U Forge{12.18.1.2016} [Minecraft Forge] (forge-1.10.2-12.18.1.2016-failtests-universal.jarx)

You are using outdated Forge.

Not sure how that is possible?
I'm using forge-1.10.2-12.18.3.2239-universal.jar
I will have CreeperHost take a look.

It appears the file was corrupt. Re-installation seems to fix the problem with forge.