If you have encountered this fatal error because of Linters 
This is the way to fix
- Choose the target you are working on
- Choose Build Phase tab
- At Run Swift Linter section, remove the path of .swiftlint.yml file if (any) or tail the path of .swiftlint.yml to the root directory
-
Command B to recompile code base
The reason is the compiler will find the configuration in the present directory if any otherwise the root directory will be set by default