With the Reborn 3 template when loading a world minecraft crashes due to a server tick loop:

Description: Exception in server tick loop

java.lang.ArrayIndexOutOfBoundsException: 10
at silly511.backups.BackupManager.restoreSaving(BackupManager.java:141)
at silly511.backups.BackupManager.serverTick(BackupManager.java:56)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_150_BackupManager_serverTick_ServerTickEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
at net.minecraftforge.fml.common.FMLCommonHandler.onPreServerTick(FMLCommonHandler.java:279)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:657)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:185)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
at java.lang.Thread.run(Unknown Source)

It looks like it might be a issue with your backups. Care trying to remove all your backups and then try again

Im going to close this assumbing its resolved, if this comes up again respond again and ill reopen