show_in_rest false disable Gutenberg

Yes it is. As noted in the documentation for register_post_type() (emphasis mine):

‘show_in_rest’
(bool) Whether to include the post type in the REST API. Set this to true for the post type to be available in the block editor.

This is because the block editor (Gutenberg) is completely powered by the REST API. If the post type is not accessible via REST then the block editor cannot load or save the post.

Related Posts:

  1. Enable Gutenberg on custom post type
  2. Creating conditional blocks for WordPress Gutenberg
  3. Add class to Gutenberg Editor for Custom Post Types
  4. How to filter by custom post type on Gutenberg “Latest Posts’ block
  5. Gutenberg: Sidebar for specific post type
  6. Gutenberg how to make attribute to save to meta
  7. How to add button to post page WordPress 5.x
  8. WordPress Gutenberg-Block with ESNext (withState, withSelect)
  9. The editor has encountered an unexpected error. // TypeError: Cannot read property ‘prefix’ of null
  10. Display different gutenberg template from selected post attributes
  11. WordPress Rest API only returns content when posttype has editor capability
  12. Lock post meta block at the bottom of a custom post type
  13. How can I list all custom post types in a block
  14. Gutenberg Featured-Image-panel missing when user with custom role edits Custom Post Type
  15. Adding a Gutenberg-like custom field on a custom post type
  16. Classic editor showing in Gutenberg when creating a custom post type
  17. Creating template with h3 block (block editor)
  18. How To Enable Block Editor (Gutenberg) for Existing Post Type via functions.php
  19. How to make a custom taxonomy selectable in post publish area?
  20. I can’t choose the custom taxonomy in my custom post type on Gutenberg
  21. Parent field missing from custom post type in the block editor
  22. How to get the parent of a non-hierarchical custom post type being edited in Gutenberg
  23. post_type_link not working in gutenberg
  24. What is the recommended / best way to do this: Event calendar post/type in a block-based theme?
  25. Getting meta in editor plugin, and event triggering issue
  26. Save the post parent in a custom post type in Gutenberg
  27. WordPress CPT save metadata in gutenberg
  28. Can I override a CPT template on a per post basis with Gutenberg block editor?
  29. Query Post Object in WP Admin
  30. How to display “Category and Post_tag” component in a CPT Gutenberg edit screen?
  31. Combine multiple getEntityRecords calls
  32. Custom post type editor uses old tinyMCE
  33. Use core block functionality in a custom block gutenberg
  34. gutenberg message
  35. How do I assign a block template (.html) to a custom post type?
  36. Custom post type set default template using block editor
  37. CPT: Enable Gutenberg, but disable editor field
  38. Select custom post type do display from page editor
  39. How add Filter by Tags and by categories to custom post type in Gutenberg block
  40. Is it possible to add the Gutenberg block editor to a custom taxonomy?
  41. How to debug failing updates for custom post type?
  42. Some posts not displaying by taxonomy term
  43. Can you programme the selected page template to display block patterns automatically?
  44. Possible to limit internal link search to post types with Gutenberg editor?
  45. Custom Gutenberg block problem – This block has encountered an error and cannot be previewed
  46. Create a shortcode to display custom post types with a specific taxonomy
  47. custom slug for custom post type
  48. Get all authors with at least one post of ‘custom post type’
  49. Returning search results by relevance, including Custom Post Types
  50. It is possible to get a list of post types asociated to a taxonomy?
  51. Sorting for each custom taxonomy
  52. ascending order custom post type
  53. New WP_query in template not working with CPT+category on some pages
  54. Custom Post Type rewrite redirects to homepage
  55. Displaying a specific post in a wp query by post id
  56. How to remove custom post type name from base url?
  57. Set up a Child/Parent relationship with a Custom Post Type
  58. get_posts of Custom Post Type AND Custom Taxonomy
  59. Tag page with Custom Post Types not returning any posts
  60. Pagination of Custom Post Types not Changing Posts
  61. How do I create custom fields for multiple post types?
  62. Pagination issue on category.php using custom post type query
  63. How to add custom field to view-edit post type page
  64. Pages are not saving due to custom post type
  65. How to get all tags of a custom post type by id
  66. Losing Nav Active State in Menu
  67. How to hook one custom post-types post to another?
  68. Custom select query for taxonomies that have posts categorized in another taxonomy
  69. Custom posts template page
  70. Add Previous/Next Buttons to CPT Single Pages Only
  71. Role capabilities issue
  72. Dynamically insert code to custom post type loop
  73. Showing User’s Post Counts by Custom Post Type in the Author.php?
  74. How To Post WordPress Custom Post Types to Twitter via IFTTT
  75. Custom Post Type Category URL
  76. Do I need to use another custom post type for 1 post that differs from all of the others?
  77. CPT as Product in WooCommerce
  78. Increasing the default number of posts in custom post types
  79. Calling related posts to a custom post type, taxonomy & Tag id
  80. How to get custom post type title, excerpt, thumbnail and permalink by post ID?
  81. Prevent user from editing others posts
  82. how to redirect to a custom post template
  83. How to get the custom post data using post id in WordPress?
  84. Should I use a custom taxonomy or custom post type for grouping a list of panels associated with a group of tests?
  85. Unknown Post Meta Records
  86. CPT post doesnt shows tags and category on backend admin page
  87. Adding a nav menu for a custom post type
  88. Custom taxonomy- only output relevant terms
  89. Post types showing tables…Can I do that?
  90. Registering an optional custom post type from a plugin
  91. Dropdown switching subcategories portfolio
  92. Weird capabilities / roles behavior
  93. Generate custom RSS from a plugin
  94. How to Arrange Support => Thumbnail
  95. Filter custom post type by tags
  96. Displaying posts exclusively in their category (not parent)
  97. Can’t make permalink of CPT work
  98. Paged within a custom content type template [duplicate]
  99. Generating custom URL before post is published
  100. Setting a Master Menu on a Custom Post Type
tech