Hi, I will be happy to help you, but I need more information, and possibly the code, so we can understand why it is not able to open the include file.
The error is saying that it is not able to open the file “CreatureBase.h”. This could have different causes.
One might be that your file is inside a folder that is not directly inside/underneath the public folder (e.g. Public/Core). Another possibility is that in the .h file the generated include is not the last one. However, without the code it is harder to find the error.