ok from the drop down the K2 is gone from the quick icons it is still there... thankfully. Where is it?

Sounds more like a riddle than a support question :) Have you tried clearing browser cache ?

yes.

and there is another thread where many people have posted the same problem.

Hi Christian,

This can be fixed by adding the proper row in the database, if this row is missing.
Please confirm that the K2 disappeared from the backend components menu, and let me know the versions of K2 and Joomla