This problem can occur under the following cases:
1. You forgot to include some Frameworks or static libraries in “Link Binary With Libraries” section of build phases tab.
2. You fail to include the .m files in Compile Sources section of build phases either in your Application project or in your own static library.
3.Build Active Architecture only setting is wrong are multiple values.
4. Using -all_load and -force_load sometimes causes this. I have not found the reason.
Build phases is a tab in your project’s target.