This was a new one to me, I’ve run hundreds of wordpress sites over the years and only today did I get this one.
Problem: Missing Categories from wordpress posts… IE if you view each blog post on the site, you can see that each post is ‘uncategorized’ and therefore being out of sync. BUT, you can still browse by URL to the category and tag pages just fine – which is the odd thing. If you log into the wp-admin you can see that there are no categories there at all, but if you try and add a new one with the same slug name it’ll error and tell you there is one. Super Odd.
Anyway – after much research around the web I found the following advice which worked for me.
” In my case, the issue was that my /tmp/ dir on my server, which is its own partition, was full. In my case, I noticed this by running df -h.”
I contacted my hosting provider and they responded saying that they had a problem with their tmp directory earlier… and now it’s fixed.
That is the first course of action – most people saying the hosting company sorted it for them / or that it was fixed automatically in due course.
In my opinion – just get in contact with your hosting provider and let them know.
Let me know how it goes 🙂