According to the log this isn't directly caused by your mod. However, I get this error only when I have your mod in my modpack.

The following is the line of the log that's relevant to the error:

25.783 Error Util.cpp:57: Error while loading recipe prototype "slagCopper" (recipe): No such node (icon)
Modifications: BobExtended › angelsrefining › ShinyBob

EDIT:
I looked at your forum page and found that it's not currently compatible with Bob's mods and Angel's mods. That's probably the cause.
I'd like to use your mod along side those though, so I'll check up on this mod to see if/when it is.

Yo, just playtesting the mod and found that the second wooden circuit showed up in recipes, but was not in the crafting menu. This made it so I could not do anything in you mod. This was in the newest version.

It's currently not compatible with some big mods like bob's, so maybe the problem comes from there.