Issue is temporarly fixed.
Please do following.
Following 2 modules data source problems.
a. Top Stories , NSP GK4 module, check to make sure selected data source does exist in case you deleted items / articles.
b. More News , NSP GK4 module, check to make sure selected data source does exist in case you deleted items / articles.
c. Tabs , Tabs GK5 module, related with step b above as data source is More news.
I have disabled above modules for now.
Also make sure your K2 directories are writable so it can display images, see following admin link
Components > K2 > Information , on right Directory Permissions.
See you around...