Xcode 9 - linker command failed with exit code 1

Question

While compiling the application getting as following error

" compiled with older version of Swift language (3.0) than previous files (4.0) file "

Could you please help me?

Answer 1

Use the xcworkspace to build instead of the xcproject?

This usually happens when using Cocoapods and you are building from the xcproject which doesn't know about the cocoapod libraries.