Xcode "Undefined symbols for architecture i386" Error without any change on code, all of a sudden

Undefined symbols for architecture i386: "_OBJC_CLASS_$_EMDenemeSinaviCell", referenced from: __TFC8EduMobil24EMAssesmentEvalenter code hereuationNEW9tableViewfS0_FTCSo11UITableView21cellForRowAtIndexPathCSo11NSIndexPath_CSo15UITableViewCell in EMAssesmentEvaluationNEW.o ld: symbol(s) not found for architecture i386 clang: error: linker command failed with exit code 1 (use -v to see invocation)