duplicate symbols for architecture i386 clang

I've seen several posts on google and stackoverflow related to this error, I've read all of them but still fetching the problem , I will be glad for a solution. Here is the error mesage I recieve when compiling ...

directory not found for option '-L/Users/somefolder/Documents/Bharat/MyApp copy/GoogleAdMobAdsSDK' duplicate symbol _OBJC_CLASS_$_AppDelegate in: /Users/madept/Library/Developer/Xcode/DerivedData/Alpha-dvvymdlmzseytagllsmbbrxdgutz/Build/Intermediates/Alpha.build/Debug-iphonesimulator/Alpha.build/Objects-normal/i386/AppDelegate-56890B6B994A4284.o

Thanks.

Solution 1:

Another reason this error often happens is accidentally importing the .m file instead of the .h.

Solution 2:

Steps:

1. Check Build phases in Target settings.
2. Check if any file exists twice or once.
3. If file exist twice delete one. If not delete file in the bottom which is the latest one.
4. Build again.