I'm having a big problem with my WP instance which is frustrating. Every time I add a new Category ( a simple default category with no custom posts or taxonomies ) it adds, as expected, that new category with that ID ( for example 6 ). When i edit my menu and save changes, all the categories get removed without reason. The "funny" thing is this:
- I create category "News", which ID is 6;
- I edit menu, so all the categories get removed
- When i re-create category News, it reassigns ID 6, which was the ID it had got before.
So, I've tried watching DB changes, and I've found something interesting. In "wp_term_taxonomy" table, I see all the categories with taxonomy "category" and their associated ID ( for example, number 6 as before ). All the "term_taxonomy_id" are "0" and this is quite strange, but when i save my menu, all the entries of this table become "nav_menu" as taxonomy.
This is really frustrating, I don't know what is causing this error because i've also re-installed WP on another instance with re-importing DB. Can someone help?