The main cause of this problem is not having a Porfolio page setup to the portfolio page template, or having two pages linked to the same template. Other portfolio post issues can also be caused by not having Permalinks setup, or a conflicting plugin breaking the portfolio slider.
Verify Your Posts
- From the WordPress Admin, click on
- Locate the page you are using as the main portfolio page. If you do not have one, create one.
- Make sure the Portfolio page template is selected from the Page Attributes menu on the right side before publishing/updating.
- Delete any other pages linked to the portfolio page template. Check your link and empty the trash to ensure any duplicates are totally gone.
Verify Your Permalinks
- Go to → .
- Select anything but the default option and click Save.
Do this even if you had a non-default option selected. This causes WordPress to regenerate your URLS or Pretty Permalinks, and is required every time you create a new page using a special page template, activate a new theme, or on other rare occasions. Do this anytime you get a 404 error where you know content should be.