Noob - can't get example project to build - ofXml.h:4:20: fatal error: ofMain.h: No such file or directory

I am just coming to OPenFramworks from Processing - I have downloaded OF and installed Code::Blocks.
To try things out I copied the emptyExample folder into apps/myApps and double clicked on emptyExample.workspace to open the project in Code::Blocks.
The project opens fine but when I click the build icon the build fails with the error message below:

D:\Program Files\Openframeworks\of_v0.8.4_win_cb_release\libs\openFrameworks\utils\ofXml.h:4:20: fatal error: ofMain.h: No such file or directory.

In the projects tab I see that the workspace contains two projects - EmptyExample and OpenFrameworksLib.
OpenFrameworksLib has a folder ‘openframeworks’ with sub-folders with what looks like cpp and h files for standard
libraries. It also shows a file ‘ofMain.h’ but the icon shows a break or tear and if I try to open the file I get a dialog saying the file does not exist.

Can anyone point me in the right direction - what am I doing wrong?

Are you sure you didn’t change the directory structure in any way?
Did you try the other examples?
Did you try making a new project using the Project Generator?

Many thanks for reply Autofasurer - The problem seems to be solved - at least the app is building now - It was my own stupidity - I somehow must have deleted ofMain.h from the OF lib directory - I restored it from the recycle bin and the project built OK