Custom Post Type + 20k posts = blank/404 within Admin edit.php [duplicate]

I do not think that there is any sane way to sort this issue with the amount of posts you have except than setting hierarchical to false. Setting hierarchical to true has huge impact on performance and aren’t really meant for use in custom post types.

If you do not need a parent/child relationship between posts like the build-in post type page have, then you should really set hierarchical to `false. If you really need that relationship, then you are pretty much stuffed unfortunately. With the amount of posts you have I cannot see any viable solution to sort your issue

Just a tip, remember to flush your permalinks after setting hierarchical to false

Related Posts:

  1. Backend search; include CPT meta?
  2. How to programatically set the post title of a CPT on wp-admin
  3. Display custom fields from custom posts in RSS feed
  4. Tracking changes in admin-page so user gets warning when leaving the page
  5. It’s possible to hide body copy box for a custom post type?
  6. Custom Field values not Showing in Edit Page of Custom Post Type
  7. Change Post Meta via AJAX from the posts list table
  8. WP Admin Dropdown List Filter for custom (ACF) field on custom post type(s)
  9. Sort custom post column by generated value?
  10. Simple Data picker meta box
  11. Query Distinct Taxonomies of Custom Post Type
  12. Custom post type won’t take my custom fields
  13. Show a custom field instead of username in the backend author area
  14. Add meta value to custom post type on publish
  15. convert custom query to wp_query
  16. Wrong request query on cpt and tax
  17. How can I dynamically add a post to a custom post type which uses a custom field?
  18. Admin Pointers on a custom post type
  19. Filtering custom post type on a combination of custom taxonomies and custom fields?
  20. Custom Posts Types as Custom Fields
  21. Get image post ID in media upload
  22. using $wpdb to get custom post type with term
  23. Why is my select meta data not saving?
  24. dynamically add a custom field or metabox to custom post type [duplicate]
  25. Give a permalink to Custom Post Types without title
  26. Add a button or image button that calls wp functions in the wp-admin
  27. Role scoping for contributors down to the field level
  28. How to implement a Google map store locator
  29. Creating a Custom Post as a repository for theme constants
  30. Converting the_content string to an array?
  31. search also in taxonomy, tags and custom fields
  32. Random image from tag/custom type on sidebar
  33. How to stick custom post at the top in search results
  34. Selecting a post in Dashboard
  35. Custom Post List View: Page or something else?
  36. How do I create custom fields for multiple post types?
  37. Custom admin post.php page
  38. Add field to all custom post types
  39. Query & Order posts by custom fields
  40. Custom Taxonomy back-end customizations
  41. Filter custom posts using auto populated dropdown selectors
  42. How do I display content to users who are not logged in instead of 404 on Private custom posts?
  43. How do I associate a custom post type with another through a taxonomy or storing an ID in a custom field?
  44. How to add a custom-post-type post within another custom-post-type post edit screen using AJAX?
  45. Custom post type content using custom fields without template
  46. Cannot add custom field to “orderby” parameter in Rest API
  47. What is the recommended / best way to do this: Event calendar post/type in a block-based theme?
  48. retrieve Meta field value from CPT and set those values as Image Meta Field “Title”
  49. Having unique constraints for custom fields in a custom post type
  50. Help with Elementor Pagination CPT archive 404 problem
  51. Querying Two Custom Post Types with OR Not Working
  52. How can I get the number of custom post type posts that have a specific attachment image set?
  53. Trash / Draft a WordPress custom post after custom date field expires
  54. Set a maxlength for the title input in a custom post type
  55. Posting to a Custom Post Type from front end – user generated content
  56. Bulk Update Custom Fields for Custom Post Types
  57. How can I use get_post_meta with add_rewrite_rule to build custom permalinks?
  58. Visual editor issue by having multiple tiny mce editors in a CPT
  59. WordPress Custom Fields Won’t Save
  60. Update Post Meta for a logged in user
  61. Problem querying Custom post type by custom fields
  62. Found 2 elements with non-unique id (#_ajax_nonce) and (#_wpnonce)
  63. Add custom field to Posts and sort by it
  64. Orderby CPT custom fields not working
  65. WP_Query order by custom field, then randomly order some of results
  66. A better way to add a meta box to custom post types
  67. Rows with custom columns not well formatted after Quick Edit save
  68. Trouble with CPT Child 404
  69. Plugin – Combine Meta Box Input Fields into single saveble record
  70. Two Custom Post Types Many to Many Relationship
  71. Filter term taxonomy metabox in custom post type
  72. Show custom post type relationships by taxonomy
  73. get_post_meta not working on publishing
  74. Query custom post type with ACF Date
  75. Custom setting to show or hide field
  76. Custom Meta Field – Remove comma from string with str_replace
  77. CPT post count is 0 for the authors in the User list
  78. Store CPT ‘Reviews’ average ratings to a WordPress DB table or to a DB custom table?
  79. Using custom field content as expression in IF statement [closed]
  80. Meta Query Not Returning Output Despite Having Matching Values
  81. Using taxonomy term in CPT permalink – Pages 404’s
  82. Addition of custom option panel crashes Media Library & Admin Area
  83. How to create a custom post type with additional fields?
  84. Callback to custom field is not working in WordPress REST API
  85. Meta Query Filtering not working on Custom Meta Box using Radio Buttons
  86. Including metaboxes from custom post types in global search — continued
  87. ACF From & To Date Validations
  88. How do I set all of a particular post meta to a value within the custom post type I’m in?
  89. Query Multiple Custom Posts by Custom Fields
  90. Show image gallery from a custom field
  91. Using advanced custom fields from one custom post type in another custom post type / using nested shortcodes
  92. Custom post URL 404 error
  93. Dynamic dropdown select values depending on other custom field value
  94. How to render a custom post type template with custom fields using shortcode
  95. Disable saving posts as draft (make all posts mandatory regardless of the post status)
  96. Grouping metadatas into one
  97. filter custom post in rest api with custom function
  98. Get Posts by multiple custom fields is not working
  99. Single post with a Custom Post Type returns 404, when archives of the CPT work correctly
  100. Possibilities for the edit.php admin panel? [closed]
File not found.