Blank/White Screen on Frontend but Accessible backend?

I have this issue, where I can’t access the frontend without a blank page anymore. It drives me crazy.

The backend seems to be up just fine, but the frontend is white. When trying to chose another theme (twentyten) this one also returns white, already in the preview.

I’ve turned on debug in wp-config after following another thread and it has come up with the following errors:

Warning:
include_once(/home/dali/public_html/wilds/wp-content/plugins/wp-super-cache/wp-cache-phase1.php):
failed to open stream: Permission denied in
/home/wildsofo/public_html/wp-content/advanced-cache.php on line 14

Warning: include_once(): Failed opening
‘/home/dali/public_html/wilds/wp-content/plugins/wp-super-cache/wp-cache-phase1.php’
for inclusion (include_path=”.:/opt/php54/lib/php”) in
/home/wildsofo/public_html/wp-content/advanced-cache.php on line 14

What can I possibly do?

Website: wildsofoldham.co.uk

In my case, nothing about debugging and disabling themes/plugins was useful… After some research, I’ve realized that my index.php was empty!
The only content was a message saying Silence is golden.
Using a backup I had, I could get back my original index.php and get the site working again.