Hello!

I am using the new Gantry 5 with Hydrogen theme for Joomla 3.4. I have used them in 2 other sites as well but there were no problem.

In a new site, I have installed all like the other sites but I cannot add a new menu item neither Categories nor Items. Just doesn't show the list i.e. in tab Options / Select Categories.

Any idea how to solve the issue?

Hello,

Are you using K2's latest version across all sites?

yes 2.6.9 to all sites... and the same Gantry 5 with Hydrogen template.

OK... I solved the issue by making a fresh install of K2...

Nice to hear that :)