compile for iOS, unknown type name class; did you mean Class

I had for a while no issue to compile for iOS with Chilkat lib. Right now I use Xcode Version 8.3.3 (8E3004b) and latest Chilkat version (May 2017).

Didn't touched the code for 3 month or so and now get error "Unknown type name 'class'; did you mea 'Class' ? e.g. when importing #import "CkGlobal.h" I have a empty .cpp and .hpp file included in the project as described in the readme.

What else can go wrong ?