I´m having the same problem. Using Joomla 2.5.2 and K2 2.5.5. My template is JA t3 blank so i´m using the T3 framework!

I can create items and categories, but they are not showing in the backend view. Everything seems to be ok, but they are not showing. PHP version 5.3.10.

And....tried with Safari and Chrome, and seems to work fine. It might be a issue wit Firefox?

I am having the same issue...items and categories not showing in admin when using Firefox. Joomla Version 2.5. Works in Internet Explorer.

Gentle bump on this topic.

I can't see items or categories in the administration area of K2 in Safari or Chrome.
Using an older Firefox version (7.0) , I CAN see items and categories.

For what it's worth, I see the same situation using Joomlaworks Front Page Slide Show (cats only visible in FF).

Running J2.5.3 . Installed latest K2 yesterday.

Any help?

Update: On 3/26 , I installed a clone of the site on a different host and everything worked as expected: all categories and items were visible (for K2 and Front Page SlideShow).
My knowledge is limited about what could be different. Both hosts were running PHP 5.2.17.
Original host: Host Gator ; Cloned site: Blue Host

I changed all if the "Relevant PHP settings on the original site to match those on the cloned site using Cpanel's' EZEConfig, but this still did not correct the k2 problem.

Does anyone with deeper knowledge of host settings have any recommendations on what can be checked ?

URGENT!!! All my articles and categories have also disappeared!!!

Is there a soultion to this as I have to finish this site but I can't do anything?!

Joomla 1.7.4

K2 2.5.4

I have been having problems with k2 items and categories not showing in admin (Joomla 2.5.3) for the last month when I use firefox, but everything is fine when using either internet explorer or google chrome. I know others with the same problem. That's all I know. I have been looking for a solution but at least can move forward.

Has anyone tried this?:
www.ostraining.com/support-forum/joomla-support/k2-dashboard-items-disappeared-but-still-show-on-the-website/limit/100/offset/0/

Same problem on all browsers. If emty cache & cookies, k2 items appears for a while in backend and after 5 minutes disapears
After hours and hours of searching i found the solution!
the problem is once again k2...
simply DEACTIVATE the plugin: K2 SMART SEARCH everything is ok

Same problem for me, does anyone have any other solutions?

Joomla! 1.7.3 is outdated. Anyone using it should update to current latest stable version (2.5.6 currently). Also update K2 and other extensions to their latest stable versions.