What to do if suddenly all Pages on your WordPress website return a 404 ‘not found’ error except your Home Page? This error is often caused by a change made on your webhost (such as an update to software used by your host). Fortunately this is usually a simple problem to fix. Just follow these simple instructions (in step 4 below it’s assumed that your original permalink setting was Post Name).

1. Login to your WordPress dashboard.
2. Go to Settings -> Permalinks.
3. Click Default then Save Changes.
4. Click Post Name then Save Changes.

You should once again be able to reach all Pages of your WordPress website without receiving a 404 error.