Symbol(s) not found for architecture armv7 (Compiling w/ xCode)

I’m having really annoying issues compiling my iOS Project. I keep getting the error "Symbol(s) not found for architecture armv7). Full error:

> Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_FBFrictionlessRecipientCache", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_SLServiceTypeTwitter", referenced from:
      ___32-[IOSTwitterPlugin loadUserData]_block_invoke in IOSTwitterPlugin.mm
obj
      -[IOSTwitterPlugin postWithMedia:media:] in IOSTwitterPlugin.mm.obj
      -[IOSTwitterPlugin post:] in IOSTwitterPlugin.mm.obj
      -[IOSTwitterPlugin IsTwitterAvaliable] in IOSTwitterPlugin.mm.obj
      -[SocialGate twitterPostWithMedia:media:] in SocialGate.mm.obj
      -[SocialGate twitterPost:] in SocialGate.mm.obj
  "_OBJC_CLASS_$_SLRequest", referenced from:
      objc-class-ref in IOSTwitterPlugin.mm.obj
  "_OBJC_CLASS_$_FBSession", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_SLComposeViewController", referenced from:
      objc-class-ref in IOSTwitterPlugin.mm.obj
      objc-class-ref in SocialGate.mm.obj
  "_SLServiceTypeFacebook", referenced from:
      -[SocialGate fbPost:] in SocialGate.mm.obj
      -[SocialGate fbPostWithMedia:media:] in SocialGate.mm.obj
  "_OBJC_CLASS_$_FBSettings", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBAppCall", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBRequestConnection", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBWebDialogs", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBShareDialogParams", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBDialogs", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBRequest", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_FBAppEvents", referenced from:
      objc-class-ref in FbUnityInterface.mm.obj
  "_FBErrorParsedJSONResponseKey", referenced from:
      _ResponseHelper in FbUnityInterface.mm.obj
  "_FBNonJSONResponseProperty", referenced from:
      _ResponseHelper in FbUnityInterface.mm.obj
  "_OBJC_CLASS_$_ASIdentifierManager", referenced from:
      objc-class-ref in libGoogleAdMobAds.a (GADDevice.o)
      objc-class-ref in libGoogleAdMobAds.a (GADGestureIdUtil.o)
ld: symbol(s) not found for architecture armv7

I did some research, but I haven’t found the answer. I did find a possible reason, the plugins are out of date. Could this be the issue? I believe they are completely up to date.

So, what could be causing this, and how can I fix this?

Thanks for your help

Edit:
Attempts to solve this, so far:
Compile via armv6. Received different errors, see my response to meat5000’s answer
Compile via armv7s. Received different errors, see my response to meat5000’s answer
Update FB plugin, same errors.

http://stackoverflow.com/questions/21447703/applovin-undefined-symbols-for-architecture-armv7

Maybe this is still relevant.

Arm7 not supported, only 6.

Change it to 6 and it should work.