Hello Webcrawler and welcome,
The majority of problems that arise usually have to do with permission settings. If this is installed on a local system then that should not be the case. If it is on the internet, then folders or directories should be 755 and files should be 644 except for the tmp, cache which should be 775 or as you have it 777.
Does this mean that you have installed this on a local system or live?
Can you also tell us which version of Php you are using.