So, I was tinkering with one of the websites I look after and made one change to the .htaccess file. I only make one change at a time to any file so I can reverse it if things go south. After my change only the home page would load: clicking anything just reloaded the home page and showed page not found in the tab (browser) title. OK, back into .htaccess and remove my change. No luck, still only the homepage loads. Hmm.
As always, Google to the rescue. It seems this can occur when using a custom Permalink structure, which I was. Went into Settings, Permalinks and clicked Save Changes even though I didn’t make any changes. Voila! Everything working as it should. I went back and made my .htaccess change again and it worked as well.