Unhappily, the same happens to me 🙁
Hm… deactivating all other plugins turned out to fix the problem. Later I activated them again it’s still working. If the author uploads the code in github, I’d gladly play a bit more with it and help with fixing this and the other thingis.
I’ll check the code, and open a github 🙂
I have just added a new gannt http://www.wolly.info/test-nuovo-gannt/s
Now I have to understand why it doesn’t work for you
I did it on a pretty old installation that I updated to 3.8.1 before installing the plugin. Theme was Spun (from wordpress.org) and I had Better WP Security and Contact Form active. After activating your plugin, I could go to the list of charts, which was obviously empty, and after adding a new one, the list was still empty. Deactivating the plugins and switching the theme to 2014 strangely let the GANTT Options page show the list of all the created charts 🙂 Activating and returning the previous theme did not “hurt” the plugin, so now it works fine.
If you are doing some caching on the charts’ list, this might be the reason… otherwise it may be misuse of a hook or filter in the wrong place, I dunno.
I have planned a complety refactor of the plugin, creating class and adding new WP functions.
Cool! I can’t promise to be constantly helping, but the plugin will be of use to me, so I will send pull requests occassionally.
I think the problem may be here register_activation_hook( __FILE__, ‘wpit_num_activation’ );