Oh, by the way: Files & projects that already exist, run fine and the code formatting is there. Entering new code within one of these even works like it should. When working on an existing file, there seems to be absolutely nothing wrong.
Do I understand correctly, thta it is just one project that does not work, everything else is okay ?
Please post the output of
find [/path/to/projects/root-dir] -exec ls -ld {} \;
to see the permissions of the whole projects source-tree.
You can also try to create a new empty project, create empty files and just copy and paste the content to the newly created files.
Don't forget to type the correct file-extensions (cpp for c++ ...).
I still don't know what went wrong, but I do not think it's a C::B problem.