I made a site some time ago and after some days some posts were indexed by search engines. Today I changed the permalink structure from /%postname%/
to /%category%/%postname%/
.
After that, when people come to my site from search engines a 404 page not found error
appears. I want to change all old URLs to the new category base URL without any 404 error.
How can I do it?
By the way, I use Yoast plugin.