Unable to load class category from framework

[quangpc-zz]

I use this tutorial to build a small framework. I also add some categories to my framework, but when I add my framework to other project and use method from category, it said that "unrecognized selector sent to class". I search question in internet and then I add to Other linker flag "-ObjC", "-all_load" but it still does not work. Please tell me what wrong with my problem. Thanks