Duplicate category pages

Have you tried deactivating your plugins? Particularly the SEO plugin(s).

I’m seeing a canonical url being specified in both pages:

<link rel="canonical" href="https://www.benutzerfreun.de/category/allgemein/" />

and it looks like it’s being added by All in One SEO Pack:

<!-- All in One SEO Pack 2.0.3.1 by Michael Torbert of Semper Fi Web Design[257,298] -->
<link rel='next' href='https://www.benutzerfreun.de/category/allgemein/page/2/' />

<link rel="canonical" href="https://www.benutzerfreun.de/category/allgemein/" />
<!-- /all in one seo pack -->

Canonical URLs are used when you have multiple pages with the same content and don’t want to hurt Google rankings, etc. WordPress shouldn’t (that I’m aware of) create the duplicate content so I’m guessing the SEO plugin is doing that for the sake of “pretty URLs.”

I’d start by deactivating that plugin and then checking if it has a setting for canonical URLs.

If that doesn’t work, try deactivating all plugins and/or switching to a default WordPress theme like twentytwelve or twentythirteen.

Thanks for looking into this. Your tips helped me to get closer to the issue:

Its neither the plugins nor the theme. When I set the theme to twentythirteen and deactivate all plugins, I get the same result. (The canonical links disappear, though.)

So I suppose it has something to do with this: In Settings>Permalinks I checked “User-defined structure” and entered
/%category%/%postname%/

What I want is that my posts appear in “folders” for the category to which they belong, like (for the example of the category “allgemein”):
https://www.benutzerfreun.de/allgemein/geld-verdienen-mit-videos-auf-vimeo/

This works as it should, but apparently this creates the category archive page as well. Or am I mistaken?

In WordPress 3.6.1, I use:

Custom Structure https://localhost/%category%/%postname%

in Settings->Permalinks.

I only get one page. I get a 404 if I remove the category from the URL.

This is odd. I tried
/%postname%

Which works as expected – only one archive page, and all posts directly in the root.

But when I go back to
/%category%/%postname%

everything is like before… strange. Any more idea?

What version of WordPress are you running? I want to make sure I’m using the same version. (it sounds like from the Permalinks wording we may have different versions)

I use 3.6.1. The wording might be different because I use the German language setting.

OK, thanks, I thought that might be, just wanted to make sure. If I come up with anything, I’ll let you know. I haven’t been able to duplicate it.

Thanks for your help, I really appreciate this!

I did not find out why this is happening, but I found a workaround: The PlugIn Yoast WordPress SEO, which I am using anyway, has a setting in the section Permalinks where I can remove the “category” from the category URLs.

This is a solution that works for me.

Thanks for the update. Good to know!