I've got a problem with my custom theme. The home page is loading fine but when I use a different page type, that I set in my page formats, I get an error.

The error says: can't find 'rootPath/concrete/themes/myTheme/default.php. I noticed this path is wrong (a concrete folder extra?). I got the same problem when im using $this->getThemePath() in the header. Weirdly im still able to use the dashboard, the home page and some other single pages. I've looked on multiple forums and I haven't found a single result yet. HELP me please.