Ok, figured it out myself! I had used add_filter to customize the password form in order to add css classes. Everything in add_filter was either old or simply wrong. I found it in a tutorial, but this has been a lesson to me. Never trust code found on the web unless it from the Codex or an absolute expert.
EDIT: Just found the same piece of code in the Codex as well *facepalm. It says “THIS NO LONGER WORKS” above it, but then why is it still in the codex? To anyone having this problem as well: in case you have used the code from here: Using Password Protection: Password Form Text you’ll get problems in newer versions of WordPress.
Related Posts:
- How to protect pages with double authentication: password + email (in custom field)
- How can I safely increase the character limit for post passwords?
- Is it possible to direct users to a certain post based on a password entered on the home page?
- Hide password protected posts in admin
- 404 error after publishing a post
- Some posts returning 404 instead of displaying post
- Custom post type single (permalink) throws a 404 error
- Unable to modify(update) posts – Page not found
- Debugging WP routing
- How to lock a post or page
- PHP Notice error (when on 404 page)
- Locked/Unlocked in title
- Getting a 404 error when clicking edit page
- 404 on paginated blog pages
- How to verify wp user password by sql query in wp? [closed]
- How to display content from the main blog on another from multisite network as it would be its own
- Why does my site often display 404 on subpages?
- custom post template file not shown, instead all the time 404.php
- One post on my website is going to a 404 page
- How do I locate the exact location where this error is occurring 404 page not found
- 404 error on default post type and default taxonomy fronted page
- Remove password protected posts from default RSS feed
- Problems with Page Not Found
- Display password protected posts to logged in users
- Change the color of the Password Protected Post titles
- Posts and Pages: 404 Page not found
- If post does not exist, do something
- Prevent 404 of Author pages without posts
- How do I check if a post is password protected?
- Using WP page password protection as defacto login
- including 404 page in post page
- 404 error on every post and page other than home
- Get post title of faulty link on 404 error page
- Getting 404 when using rewrite rule for posts
- Cannot Create a new Post [closed]
- Post pages are redirecting to the 404 page in wordpress
- Redirection – bulk edit 404s to new tomain
- Stop WordPress automatically adding tags to post content
- how to get a different html for odd/even posts?
- How do I create a link that will always show the latest post?
- How to display posts by current user/author in a custom page template?
- featuring old articles without messing up with the archive
- Is there a plugin that creates a WP post based on a Twitter account’s hashtag?
- Human Time Diff, change mins to minutes
- “Lost password” page triggers 404
- same template for multiple custom post type single
- Allowing the SoundCloud player to appear in a post excerpt
- Display the Content of a Post with qTip2
- Scheduled posting not working
- Converting multiple loops into one single loop with pagination
- Run a function when post is deleted?
- Exclude posts w/ specific post_meta on Rest API endpoint
- Should $found_posts be returned as string in ‘found_posts’ filter hook?
- How to change wordpress dates to native language (even if the languge not available i wordpress)
- Theme removed “Edit Post” link on the front end. I wish it back
- WP_Query orderby not working with meta_value_num and menu_order
- Custom WP_Query with complex ‘post_status’ argument
- Saving category to a post, before publishing the post
- Adding a blog archive with pagination using WP_Query
- How to get Tags with specific post id
- User Selectable Delete of Pages
- Get post content with all filters applied, knowing post id
- query post limits
- is_page() and is_page_template() not being differentiated
- Post type no single page
- Get attachments only for this post
- How can I list posts by author?
- Querying another post category to match current post and display in loop
- Microformats in a single post – layout conflict
- Conditional css for custom post type
- Get author posts count after excluding a category
- How to add PHP code snippet to all Post pages?
- MySQL: Possible to replace all of wp_posts.post_content(id#) via UPDATE + REPLACE + SELECT?
- Different background colors for posts with WordPress
- I want to add another search box on posts page in dashboard
- Menu does not foward to the linked posts
- How to get post creation date?
- How to set the post permalink using the WordPress REST API?
- Multiple post in One Loop in wordpress
- Order posts inside bootstrap card columns
- Save ACF with a save button on a post
- Delete attached images from posts
- Unable to edit or post after enabling SSL
- Clicking on a Post takes 10+ seconds for the server to respond, Pages will respond immediately
- Schedule image post on download
- Show posts in a parent directory [duplicate]
- WordPress infinite post cycle problem
- How can I access my posts on my wordpress site, now I’ve lost the domain name for it?
- Page not loading content – Body archive – page
- External link not showing on post but showing on comment
- Why is $_POST Empty in Profile Edit Admin?
- TCPDF and permalinks
- How can i show only 30% of the “the_content(“More…”)”?
- How do i put a dropdown list of ALL my post in the sidebar menu?
- how to edit attachments?
- Next and Previous buttons are not showing on home page for post
- NewsPaper WP Theme – Additional Related Posts Filter by Time (divTag composer)
- How to make the Post Author name fixed as “Editorial Staff” even if there are multiple authors?
- Preset category checkbox from URL parameter when creating new post
- REST API – Retrieving posts with custom status