Q:

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

I get the Undefined symbols for architecture i386. Here's what I did:

I checked many times for miswriting .h or .m extensions.
I deleted Framework Search Paths and then wrote ./ being defined as "Recursive" as it was provided as a solution but it did not work either.
Architecture settings is now set as $(ARCHS_STANDARD).
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_EMDenemeSinaviCell", referenced from:
     __TFC8EduMobil24EMAssesmentEvaluationNEW9tableViewfS0_FTCSo11UITableView21cellForR        owAtIndexPathCSo11NSIndexPath_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)

When i change the current Cell Class i am using to another Cell Class it does not give any error. But it gives the following warning:
file was built for i386 which is not the architecture being linked (x86_64): 

How can I solve this error?

A:

This solution solved my problem,
https://stackoverflow.com/a/26561570/3924964
The implementation part was missing in Cell file. :(

