cloudsky

im currently using:
Permalink: /%category%/%postname%/
this error still occur while Yoast is inactive.
Yoast version6.0
Wordpress (Latest v4.9.1)

and one more thing, i found this:
i cant use numbers as the post name slug, if i use all numbers post name slug, i visit the page it will show “Page Not Found”

so the solution i have not using all numbers as the post name. like this
example.com/category/slug/123456 (this shows page not found)
example.com/category/slug/ABC 123456 (without “full numbers” name url it worked fine)

• This reply was modified 6 years, 11 months ago by cloudsky.
• This reply was modified 6 years, 11 months ago by cloudsky.

more info: the first time i saw this error is when i visit wordpress dashboard and i see a massage “Yoast Plugin: we have notice that you have changed your post name, you need to set redirect to Error 404 page.”

what does redirect means?

thank you!!!