Editor unusable in WP 5.0.2

[anonymized_13628566]

1. Click on "Add Post"
2. New page opens with white screen and error msg:

TypeError: Cannot read property 'show_ui' of undefined
    at https://blog.flowl.info/wp-includes/js/dist/editor.min.js?ver=9.0.6:55:240816
    at i (https://blog.flowl.info/wp-includes/js/dist/vendor/lodash.min.js?ver=4.17.11:6:91)
    at An.filter (https://blog.flowl.info/wp-includes/js/dist/vendor/lodash.min.js?ver=4.17.11:99:338)
    at https://blog.flowl.info/wp-includes/js/dist/editor.min.js?ver=9.0.6:55:240781
    at ph (https://blog.flowl.info/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.6.3:97:88)
    at eg (https://blog.flowl.info/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.6.3:125:307)
    at fg (https://blog.flowl.info/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.6.3:126:168)
    at wc (https://blog.flowl.info/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.6.3:138:237)
    at fa (https://blog.flowl.info/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.6.3:137:115)
    at gg (https://blog.flowl.info/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.6.3:135:196)

I have disabled all plugins and the bug still appears.

[anonymized_13628566]

Edit:

• The input mask / editor appears for a few milliseconds before the the site turns white.
• Hitting "Attempt to Recover" has no effect (it's just a reload, isn't it).
• Editing existing posts leads to the same behaviour.
• Appears in most recent Firefox and most recent Chrome.
• I have nothing special installed and I always use default settings concerning WP / Editor.
• No difference between "Gutenberg" enabled and disabled.

[aduth]

Based on the text, I suspect the source of the error is this line of code:

​https://github.com/WordPress/gutenberg/blob/7e72ba5252d5c22d35f3aaedb0b68b59e0011cd1/packages/editor/src/components/post-taxonomies/index.js#L21

Could you try running the following code in your browser's developer tools console, and pasting the result here?

JSON.stringify( wp.data.select( 'core' ).getTaxonomies( { per_page: -1 } ), null, 2 )

Instructions for accessing the console in Chrome can be found here:

​https://developers.google.com/web/tools/chrome-devtools/console/

---

Possible related issue? ​https://github.com/WordPress/gutenberg/issues/11463

Do you have a custom permalinks configuration for your site?

[subrataemfluence]

I could not reproduce the issue.

Firefox version: Quantum 64.0
Chrome version:71.0.3578.98 (Official Build)

I am putting output of

JSON.stringify( wp.data.select( 'core' ).getTaxonomies( { per_page: -1 } ), null, 2 )

This might help @DanFromGermany to compare

[
  {
    "name": "Categories",
    "slug": "category",
    "capabilities": {
      "manage_terms": "manage_categories",
      "edit_terms": "edit_categories",
      "delete_terms": "delete_categories",
      "assign_terms": "assign_categories"
    },
    "description": "",
    "labels": {
      "name": "Categories",
      "singular_name": "Category",
      "search_items": "Search Categories",
      "popular_items": null,
      "all_items": "All Categories",
      "parent_item": "Parent Category",
      "parent_item_colon": "Parent Category:",
      "edit_item": "Edit Category",
      "view_item": "View Category",
      "update_item": "Update Category",
      "add_new_item": "Add New Category",
      "new_item_name": "New Category Name",
      "separate_items_with_commas": null,
      "add_or_remove_items": null,
      "choose_from_most_used": null,
      "not_found": "No categories found.",
      "no_terms": "No categories",
      "items_list_navigation": "Categories list navigation",
      "items_list": "Categories list",
      "most_used": "Most Used",
      "back_to_items": "← Back to Categories",
      "menu_name": "Categories",
      "name_admin_bar": "category"
    },
    "types": [
      "post"
    ],
    "show_cloud": true,
    "hierarchical": true,
    "rest_base": "categories",
    "visibility": {
      "public": true,
      "publicly_queryable": true,
      "show_admin_column": true,
      "show_in_nav_menus": true,
      "show_in_quick_edit": true,
      "show_ui": true
    },
    "_links": {
      "collection": [
        {
          "href": "http://local.subratasarkar.com/wp-json/wp/v2/taxonomies"
        }
      ],
      "wp:items": [
        {
          "href": "http://local.subratasarkar.com/wp-json/wp/v2/categories"
        }
      ],
      "curies": [
        {
          "name": "wp",
          "href": "https://api.w.org/{rel}",
          "templated": true
        }
      ]
    }
  },
  {
    "name": "Tags",
    "slug": "post_tag",
    "capabilities": {
      "manage_terms": "manage_post_tags",
      "edit_terms": "edit_post_tags",
      "delete_terms": "delete_post_tags",
      "assign_terms": "assign_post_tags"
    },
    "description": "",
    "labels": {
      "name": "Tags",
      "singular_name": "Tag",
      "search_items": "Search Tags",
      "popular_items": "Popular Tags",
      "all_items": "All Tags",
      "parent_item": null,
      "parent_item_colon": null,
      "edit_item": "Edit Tag",
      "view_item": "View Tag",
      "update_item": "Update Tag",
      "add_new_item": "Add New Tag",
      "new_item_name": "New Tag Name",
      "separate_items_with_commas": "Separate tags with commas",
      "add_or_remove_items": "Add or remove tags",
      "choose_from_most_used": "Choose from the most used tags",
      "not_found": "No tags found.",
      "no_terms": "No tags",
      "items_list_navigation": "Tags list navigation",
      "items_list": "Tags list",
      "most_used": "Most Used",
      "back_to_items": "← Back to Tags",
      "menu_name": "Tags",
      "name_admin_bar": "post_tag"
    },
    "types": [
      "post"
    ],
    "show_cloud": true,
    "hierarchical": false,
    "rest_base": "tags",
    "visibility": {
      "public": true,
      "publicly_queryable": true,
      "show_admin_column": true,
      "show_in_nav_menus": true,
      "show_in_quick_edit": true,
      "show_ui": true
    },
    "_links": {
      "collection": [
        {
          "href": "http://local.subratasarkar.com/wp-json/wp/v2/taxonomies"
        }
      ],
      "wp:items": [
        {
          "href": "http://local.subratasarkar.com/wp-json/wp/v2/tags"
        }
      ],
      "curies": [
        {
          "name": "wp",
          "href": "https://api.w.org/{rel}",
          "templated": true
        }
      ]
    }
  }
]

[anonymized_13628566]

The Permalink was the problem, although I have disabled Gutenberg.

My Permalink structure is /%year%/%postname%/.

Why is something so basic and core related causing this kind of behaviour... How can I REALLY disable Gutenberg?

[subrataemfluence]

You can install and activate Classic Editor plugin. It will keep you going with the editor we are familiar with!

​https://wordpress.org/plugins/classic-editor/

Replying to DanFromGermany:

The Permalink was the problem, although I have disabled Gutenberg.

My Permalink structure is /%year%/%postname%/.

Why is something so basic and core related causing this kind of behaviour... How can I REALLY disable Gutenberg?

[anonymized_13628566]

Going to install the classic editor!
Thank you very much, for your quick and helpful responses.
Please excuse me when this is not really a core related bug and feel free to close or delete it.

Replying to subrataemfluence:

You can install and activate Classic Editor plugin. It will keep you going with the editor we are familiar with!

​https://wordpress.org/plugins/classic-editor/

Replying to DanFromGermany:

The Permalink was the problem, although I have disabled Gutenberg.

My Permalink structure is /%year%/%postname%/.

Why is something so basic and core related causing this kind of behaviour... How can I REALLY disable Gutenberg?

[desrosj]

Closing this out as it the reporter was able to figure out the issue.