If you have a problem with your WordPress® installation's Permalinks, you can potentially fix the issue by enabling a different Permalink setting, and then enabling your original Permalink setting.
To Fix Permalink Issues
- Log in to your WordPress admin panel.
- Click Settings.
- From the Settings menu, click Permalinks.
- Note which kind of Permalink you currently use.
- Select any Permalink setting other than the one you currently use, and then click Save Changes.
- Select your original Permalink setting, and then click Save Changes.
If that does not fix the issue with your WordPress installation, see WordPress' article, Using Permalinks.