Hello, I am using K2 2.5.6 with Joomla 2.5.4. My site has been up and live for 6 months now and about 5 hours ago my K2 items disppeared and are not showing on the website or in the admin system. I get errors similar to this when i go to the items tab:

Warning: Invalid argument supplied for foreach() in /home/prodwwwr/public_html/administrator/components/com_k2/views/items/view.html.php on line 50

Please note, I am not very technical so I hope there is an easy fix.

Thanks!

That is a "warning" not a fatal error, it should not remove anything.
Turn error reporting to none in Joomla Global Settings Server Tab and the warning should go away.

What have you changed, added, or updated on your site just before the items went away?