we found the solution:
There were deleted Pages and/or Posts with the same title. We removed them and now everythings works!
Related Posts:
- Remove the blog slug from WordPress Multisite root node
- WordPress Multisite, NGINX and WordPress Subdirectory Install
- WordPress Multisite with multiple domains using Nginx
- WordPress Multisite with NGINX, subfolders, and FROM a subfolder
- NGinx + WordPress Subdomain Multi with core in Subdirectory
- NGINX Multisite Rewrite rules
- Multisite wordpress and subdomain URL collisions
- Nginx rules for subdomain multisite install (Bedrock)
- 301 Redirects for posts, category, pages from original domain to sub-domain of multisite
- Multisite WordPress nginx uploaded files throw 404
- WordPress Installation for multi-domains with nginx and php-fpm
- how do I configure nginx for wordpress multisite, it occurs ERR_TOO_MANY_REDIRECTS
- Removing /blog/ from multisites cause infinite redirection
- Subdirectory multisite – only root admin available on NGINX
- Get Permalink of Network Blog Post
- WordPress multisite subdirectory on nginx behind reverse proxy
- Multisite setup on VVV with bedrock
- How to run a subdirectory multisite install under a subdomain
- Multi-site: removing /blog from posts
- Permalinks not working using wordPress Networking with custom post types
- MultiSite Move conjures duplicate URL
- NGINX rewrite rules for sub subdomains
- Mapping subdomain to point to sudirectory site in WordPress Multisite Network
- Redirect & permalink problems after moving multisite to a new server
- How to get permalink using get_blog_post function in a multisite?
- WordPress Pages Redirecting to Root with WordPress Multisite (Sub-Directory)
- Nginx Wildcard SSL with WordPress Multisite Subdomains
- Nginx config, how can I redirect primary multisite domain, but not its sub-folders, nor other domains?
- WordPress Network (multisite) — how to ensure each site has their own admin URL?
- Nginx — WordPress multisite with root folder in own directory
- Can I safely remove banned names from WordPress?
- Help with multisite redirect issues using Cherokee OR solid nginx config?
- One blog inside another
- wordpress multisite permalink structure: mostly subdomains but not all
- How to show only blog-domain instead of the whole permalink in the loop
- Permalink with a Category and then a Post
- WordPress in subdirectory, Multisite using subdomains Nginx
- Changed sub-site to its own domain trigger 302 redirects for all page links
- What is with the one month time limit for sub directory installs for multisite network?
- unique identifier for the same pages in a multilanguage/site context
- WordPress Multisite Permalinks on mapped domain = server 404 error
- Why WordPress w/ Nginx Multisite Only Lets Admin Upload ZIP Plugins But Not Themes? [closed]
- Configure WordPress Multisite Pages with Custom Permalinks
- Setup another new subdomain root on top of multisite configuration
- WordPress multisite second site admin resulting in too many redirects error
- Possible to reverse proxy WP multisite to a separate server with NGINX?
- Multisite wp-admin redirecting to main wp-admin using NGINX
- wordpress.mydomian.com 404 Error
- Nginx rules for subdomain multisite install (Bedrock)
- WordPress Multisite FQDN Admin Access
- WordPressMU: URL change and broken permalinks/links
- Using www along with non-www for main domain in multisite installation
- Why does defining MULTISITE true change the database connection in use
- Get the post URL from wordpress posts
- Moved my site to new host now getting 404
- Network created blogs URL
- WordPress on Nginx – Missing admin/toolbar
- Remove blog slug from WPMU?
- first load of the page gives 404 error
- Nginx Multisite redirects (incorrectly) on Chrome IE and Mobile, but works (correctly) on Firefox
- Permalinks in Multisite not working
- How to remove index.php from a tag or archive page URL in the root blog?
- Multisite: should /blog go to a 404 page?
- wordpress multisite is broken in nginx but working in apache
- Multisite stuck at 1MB for max file size
- How to Control user registrations directly on sub-sites
- WordPress multisite,several different languages,page redirect?
- Prevent Deletion of Blogs
- WordPress multisite subdirectory redirect infinite loop issue
- Installing One Plugin on a Few Blogs on a MultiSite
- .htaccess 301 vs. 302 Enforcing HTTPS
- Localized WordPress content for different sub-locales of same language?
- “Organize my uploads into month- and year-based folder” Option Not Visible in Multisite
- Multisite theme control not working
- Copy Root Multisite Site
- WP Multisite with Domain Mapping : Preventing User Access to Dashboard
- Howto disable comment moderation emails for admins, but not for authors
- Renaming admin user on multisite install by MySQL
- Share contents/posts between sites in a WordPress 5.6
- Wait ajax to complete before continue loop
- Two WordPress Installs — Failed page on One Defaults to the Other
- WP Multisite Subdirectory Custom Permalinks 404
- How to enable wp-admin and wp-login only over highport
- Error while localizing communityEventsData in script-loader.php
- Display posts from one network site on another
- Multisite install on a sub-directory
- How to change a logo on a wordpress site that is part of a 7 site multisite?
- Allow users on a multisite network to only have access to one subdomain
- Admin dashboard does not show WordPress network sites
- WordPress multisite: wp-admin 403 error
- How to put a Custom Folder under one sub-site of Multisite WP?
- Nice font not working when http to https – SSL Issue
- add_action insert html
- 404 error in dashboard of subdomain of multisite
- Single installation with sub-domains for admin and separate domains for sites
- WordPress Multisites
- The wpmu_blogs_columns filter is not working
- Map WP Multisite blog.example.com to anotherdomain.com/blog?
- get_category_link() or get_tag_link() return wrong category/tag base in wordpress multisite
- Multisite subdomain microsite on secondary domain