I wonder if you have some more error messages before the Build error message.
The error message sounds like you have a pointer variable but the variable has not been assigned or something like that.
If you can post your project archive or simple sample project with which we can reproduce the problem will help others to point out the root cause.
Can you try Blink LED project from the Examples project. If this fails, then you have something wrong with the installation of Creator or you're not creating the workspace according to what Creator is expecting.
Yes, you will see an error bubble (or yellow "!") next to the declaration line for project.h, but that will go away after your first Build.
> Repeatedly removed and rearranged
If that is the case, please make sure that path name of
(1) PSoC Creator Installation path name
(2) Your Design Workspace name and path
(3) Your Project Name and path
none of above has white space (space, tab) and non-standard ascii letters such as Kanji etc.
By the way, also would you teach us your environment?
Hardware (CPU, MEMORY, HDD space)
Software (Operating system)