Apache2 is reachable, but not owncloud

My owncloud run perfectly until some hour ago. Not I cannot access it anymore.
I can access the apache2, so when I type raspberry.local, I see the apache2 debian default page, but raspberry.local/owncloud leads to "This page is not working..."

Here you can find my owncloud.log file:

sudo -u www-data php occ help maintenance:mode
is also not working, says occ cannot be found

I installed owncloud according to:

Thanks for help, i am a total beginner

Here is a very good instruction developed by experts from ownCloud.

I would recommending reading it and looking for what you have missed.

https://doc.owncloud.com/server/10.0/admin_manual/installation/source_installation.html

Hi,
You said, it was working few hours ago, and not anymore. But what did you change in between? This looks like a misconfiguration of Apache2 virtual host.

I suspect a caching issue. It was working as long as the correct configuration was in cache. Thats my thought anyway.

Thank you for alle the answers. I had a typo error in the config.php