Here is the steps for applying first-aid if a C5 site fails

1. Check .htaccess file and its file permission (Check for directory base)
2. Disable cache and clear cache from dashboard
3. Try to delete/rename /files/cache , /files/tmp directories
4. Run DB/XML refresh (use intelligent Search on top right of dashboard, search 'xml' )
5. Remove old page versions from automated job


If all these tests fails, we have to check for the server configuration which is suitable for concrete5. Just rename config/site.php and run the site , it will take us to Installation, there we can see the Environment test. Make sure everything is okay.

Still not working ? Consult a Concrete5 Developer @ manup.rav@gmail.com

Please share your techniques.....