public String getLastFontPath() {
        var path = generalPref.getString("last-font-path", generalPref.getString("last-path"));
        if (path == null || !Gdx.files.absolute(path).exists()) {
            path = Gdx.files.getLocalStoragePath();
        }
        return path;
    }
Checks every drawable path for existence. Errors are reported as a list
of DrawableDatas.
@return A list of all DrawableDatas that must have their paths resolved.
Returns an empty list if there are no errors.
core/src/com/ray3k/skincomposer/data/ProjectData.java