If so, then you need to manually update to LWJGL 2.9.x:LWJGL: 2.4.2
It appears that it is unable to add one of the recipes from Wireless Redstone(?). Could you post a console log to pastebin as well? Press the 'Paste my log to pastebin.com' button. This will add a link to the bottom of the console for the pastebin link. I know that you called it a clean install, but did you add any mods or change any mod versions?java.lang.NullPointerException
at wn.a(CraftingManager.java:200)
at cpw.mods.fml.common.registry.GameRegistry.addShapedRecipe(GameRegistry.java:259)
at cpw.mods.fml.common.registry.GameRegistry.addRecipe(GameRegistry.java:254)
at codechicken.wirelessredstone.addons.WRAddonProxy.addRecipes(WRAddonProxy.java:50)
I was hoping that another clue to the cause would present itself in a console log that might not appear in a crash log. This error is caused by minecraft not being able to access the listed file. Try adding the folder 'C:\Users\Stephen\Documents\MinecraftFTB\' to the exception list of your antivirus program. Check any boxes that say 'include sub-folders' as you do.(The requested operation cannot be performed on a file with a user-mapped section open)
Unfortunately, such a thing doesn't exist. They're all getting more and more invasive.Looks like that was what was doing it, thanks. Now I need to go find an antivirus program that doesn't make me tear my hair out.