WordPress Slug Destruction

Well, I was doing some maintenance (repurposing a site) and deleted WooCommerce from the plugins list, this caused a 500 error and I had to rename the plugins folder via FTP and name it back again to disable all plugins, I then deleted WooCommerce as I had originally intended, re-enabled all my other plugins and got back to work.

Fast-forward 10 minutes, I check to see if everything still works on the front-end, it does with the exception of the blog posts, the /blog/ slug they previously had (added through Permalinks like so: /blog/%postname%/) now rename/redirect themselves to /blogs/ and I get 404 errors on them.
If I remove the /blog bit from the permalink it works fine, but I need the slug there to differentiate posts and pages (and to justify spending 2 hours styling the blog archive page).

Has anyone ever encountered a problem like this before, know what I have done wrong or know how I can fix this?

• This topic was modified 8 years, 5 months ago by Steven Stern (sterndata). Reason: modified title - it's assumed you want help :-)