Why would adding a template file to a child theme cause an error in template-loader.php?

Your initial idea is correct, WordPress shouldn’t look for index.php if it finds category.php for a category archive. However, that may change if you don’t have file permission and ownership set properly, or if FileSystem cache is messing with file_exists() check.

Follow these steps:

  1. Make sure your child theme files are readable by the web server user. Check both file permission and ownership.

  2. Check to see if the child theme is coupled properly with the parent theme and it can get templates from parent theme if any specific template is absent in the child theme.

  3. In wp-config.php use clearstatcache(); function (before require_once(ABSPATH . 'wp-settings.php');) to clear filesystem cache.

    In case you were adding & removing those files while testing and filesystem caching those files, clearstatcache(); will help you clearing those filesystem cache that may confuse WordPress core. Once done, remove clearstatcache(); call.

Related Posts:

  1. Is it possible to override the result of get_template_part()?
  2. Child Theme: how to override variables?
  3. roots child theme can’t override header.php
  4. Load template inside a parent template
  5. Child theme TEMPLATEPATH issue
  6. Updating modified templates
  7. Child theme template file will not load
  8. Checking for page templates in child theme
  9. Should template files be copied to the child theme for editing?
  10. Why does the Full-width Template in Twenty Twelve pack so many classes into the body class attribute?
  11. How to preserve changes in templates and other files
  12. Template administration Error after WP 4.8 update
  13. Override Dokan Includes File in Child Theme
  14. lost css when overriding themes templates
  15. ACF costum date format [closed]
  16. What template is used for viewing Media Library Files?
  17. Page header on specific page is different from the rest [closed]
  18. WordPress custom template not showing in the list of available templates
  19. Parent/Child themes – both CSS files loaded
  20. Uncaught Error: Call to undefined function twentytwenty_the_post_meta()
  21. Unable to access wordpress page
  22. Child theme enqueueing style.min.css not style.css
  23. How can I make custom page templates work on child theme?
  24. WordPress Child Theme Template auth_redirect wrapper
  25. How can I add some blocks to template without changing template file?
  26. custom template – override plugin template in child theme – issue with scripts
  27. Unload templates; disable parent Template Parts using only “theme.json”
  28. How do I get the size of an attachment file?
  29. How to get slug of current category in taxonomy template?
  30. Using WordPress templating for HTML emails
  31. I put my blog on a subpage, how do I get page title?
  32. Outputting Canonical Resource URLs Across a Multisite Network?
  33. Restrict a search to a custom post type
  34. Test if page is child and has children, if so echo child pages also on grandchild pages
  35. Correct process for a new Page Template?
  36. Templates & CSS – Proper Programming Practice?
  37. A shared custom taxonomy between two custom post types
  38. Creating a custom category page with pagination
  39. WP is not using the select custom template.php that its selected for a page
  40. New Template — copy existing template and change code? [duplicate]
  41. Same template for all the terms of a taxonomy
  42. Modifying searchform.php and search.php to have two kinds of searches
  43. Create a WordPress template without navigation and footer
  44. Template redirect is_tax() not working
  45. Hide Front-End Admin Bar Including 32 px Spacing
  46. Passing variables to template parts
  47. Change directory where get_header(), get_footer() and get_sidebar() look for templates
  48. How to format shortcode’s HTML in external file
  49. Unable to include a template
  50. Turning on the 404 page on localhost
  51. Is there an action hook that fires just before a template is loaded?
  52. Twenty Eleven Child theme error when attempting to use a rewritten function
  53. What’s the equivalent of front-page.php for a custom static page?
  54. Stylesheet comment header: Which header names are mandatory? [duplicate]
  55. How to add posts list to a page template?
  56. Valid HTML in Template Part
  57. Why do I get the same excerpt for all items in my RSS feed?
  58. What is this code trying to do? It was the cause of my 20s TTFB
  59. get_post_metadata() undefined when used in loop in RSS template
  60. the_excerpt producing empty output
  61. Problem when linking out to separate file within foreach loop
  62. Conditional tags or Multiple files
  63. Getting term description in single post template
  64. Cannot edit style.css from admin panel, because the template is looking for style.min.css
  65. Can I add a default Block to my custom theme?
  66. Remove post templates from the selection box menu when creating a single post
  67. global variables in templates
  68. Real Time Page Template Preview in WP Admin [closed]
  69. Best practice to update the file header.php
  70. page-{slug}.php vs. template-{slug}.php
  71. Understanding the Template hierarchy
  72. wp_enqueue_style and different styles for blog template
  73. Can I have both front-page.php and index.php?
  74. get_header(), get_footer() from plugin template
  75. If Posted After Date
  76. how can I add a “read more” tag directly in the template?
  77. Update template without undoing all my edits?
  78. How to get and set the post tag value within WP Query from URL?
  79. The wordpress website is showing ‘w’ while it loads and in the footer
  80. how to properly include or get file contents in a wordpress theme
  81. Assign Specific Template for Custom Post slug
  82. Including template pages within another template?
  83. Why won’t the action hook wp_head accept parameters?
  84. the_post() in RSS feed
  85. Editing my loop-page.php causes posts to show on all pages
  86. How can i conditionally load taxonomy-{taxonomy}.php template php files through functions.php
  87. Search button click sends to single-custom_post_type instead staying at the same page
  88. WordPress site not loading styles on desktop?
  89. Display all page which have not a certain template
  90. ACF – Attach JS file depending on ACF field
  91. Which template(s) to override to use a different sidebar for blog, single posts, categories, blog archive?
  92. How can I alter a post?
  93. What is the purpose of the $before and $after arguments on the the_title() function?
  94. Remove ” Browse Category : ” from Archive title
  95. Using external file with WP_USE_THEMES set to false causing 404
  96. Current URL path variable
  97. Why is my no-results.php template moving my sidebar and footer into the main container?
  98. Given a page ID, how to display entire page (header/content/footer/sidebars) from a plugin hook
  99. Any way to insert text on page from a query results?
  100. If I define a variable in header.php, how do I make it available to templates?