WordPress User ID as Shortcode

From add_shortcode

…Note that the function called by the shortcode should never produce output of any kind. Shortcode functions should return the text that is to be used to replace the shortcode. Producing the output directly will lead to unexpected results…

Try changing the echos in your callback to returns and see, if that helps.

Related Posts:

  1. Shortcode outputs at the top of the_content
  2. Combining shortcode and get_template_part
  3. Escaping quotes from shortcode attributes
  4. Shortcode output always showing at top of page
  5. How to detect if a Shortcode is being called on a page?
  6. How to get current page title inside a page itself in a shortcode and in page content
  7. Short code to display a loop
  8. shortcode inside another shortcode
  9. Need MySQL Query or WP-CLI command to updates old URLs in Shortcodes [closed]
  10. Custom Shortcode AJAX 400 Bad Request
  11. WordPress core responsive video not working with shortcode
  12. WordPress gallery ‘post_gallery’ filter doesn’t work with feeds?
  13. shortcode to create dynamic dropdown box form shortcode attributes
  14. conditional shortcode not working
  15. How do I add my own custom shortcodes?
  16. Can’t seem to get [shortcode]s to work
  17. Wraping $content into link with shortcodes
  18. nested Shortcode doesn’t work
  19. Slow page loading when using a simple shortcode on the same page multiple times
  20. TinyMCE get selected text and underlying HTML
  21. Remove and restore one shortcode
  22. Rewriting WordPress Gallery Shortcode with Bootstrap Carousel
  23. other shortcodes in Contact form 7 MAILS [closed]
  24. Remove empty p-Tags in Shortcode content before non p-Tags
  25. What is a short code?
  26. Display content from another site page using a shortcode
  27. Wrap shortcode inside custom block
  28. Instagram URL is converted into oEmbed
  29. Shortcode with no attribute but has value
  30. Creating a shortcode based on users preferences
  31. Get a post’s thumbnail url or display default image in shortcode
  32. basic shortcode – Why 1st paragraph not wrapped in p tag, but 2nd is
  33. unwanted P tags in shortcode, delay wpautop not working
  34. Shortcodes and a list of IDs?
  35. Convert HTML Script to Shortcode [closed]
  36. Registration Form Shortcode
  37. Include tags in the body of a post
  38. no content after shortcode
  39. Remove shortcodes that are different (but same pattern) in each post
  40. Place a URL parameter value inside a WordPress short code
  41. Shortcodes in excerpts returning empty string
  42. Scripts for shortcode: concatenate or load separately? [closed]
  43. Print shortcode in defined area
  44. WordPress shortcodes are not working
  45. Conditionally Loading JavaScript/CSS for Shortcodes
  46. How to use/enable Pagination?
  47. Wrap Shortcodes and wpautop
  48. Shortcode called twice
  49. Favorite websites with shortened hyperlinks
  50. Best way to find all shortcodes that come with WordPress
  51. Using Variables in Shortcodes
  52. Add JS in footer via shortcode?
  53. Shortcode syntax errors
  54. Passing variable in nested shortcodes
  55. Shortcode Always Displays Default Attribute Value
  56. Can I use shortcodes in mail body
  57. Does short-code slow down my WordPress site?
  58. redirect if shortcode exists
  59. Shortcode Help Needed → attributes
  60. Video Shortcode & Video Poster Question
  61. How to use a nested shortcode to render the value of an attribute in parent shortcode
  62. ob_get_clean(); doesn’t return $value in shortcode?
  63. Ordering get_terms with ACF not displaying all terms
  64. Which wordpress function is the caption shortcode linked to?
  65. Content between shortcodes
  66. Parsing a shortcode through an author meta textfield
  67. Adding YouTube button to TinyMCE editor
  68. How to find out what handler is registered to a shortcode
  69. Shortcode strips formatting and returns at content top
  70. do_shortcode within a shortcode
  71. tiny_mce_before_init preventing custom shortcode icon appearing
  72. Custom Fields – Boolean Display of True/False to Yes/No
  73. How to display NextGEN gallery in templates?
  74. Twitter bootstrap tabs
  75. jQuery Tabs in Shortcode API
  76. Using Shorcodes in Sharing Preview and Notifications Title from Post Title
  77. Echo Extra Shortcode HTML to wp_foot
  78. How can I use a plugin shortcode inside of a html form?
  79. Disable wpautop on Shortcode attributes
  80. remove shortcode pagination for specific url referrer
  81. If statement shortcode
  82. Shortcode PHP file for two conditions passed when do shortcode
  83. update_metadata() appends shortcode data for every page refresh
  84. Gallery shortcode is empty but magically creates a gallery
  85. Add audio file to post using custom term meta field as link [closed]
  86. Display tags cloud from a specific category ID with a shortcode
  87. How to avoid one code multiple times instead do that through some function? Shortcode, but I think shortcode is not used in main theme’s core files?
  88. Shortcode appeared twice on page, one time before content, one time where it’s really called
  89. How to list child pages with excerpts, e.g. [child-pages depth=”1″ excerpt=”1″]
  90. Get current category and place it in shortcode
  91. Video shortcode outside WordPress not working with IE and mediaelement’s Flash fallback
  92. Inserting a variable into a shortcode inside php
  93. Using shortcodes that wrap around code
  94. Shortcode for Admin Theme Option?
  95. Clarify: Enqueueing scripts within shortcode only loads in footer?
  96. What makes a placeholder resizable in Tinymce?
  97. Create plugin/function to catch XML-data via Shortcode
  98. Shortcode conversion to hrml when post is published
  99. How to reuse php templates as shortcodes?
  100. Shortcode attributes from meta query variables
error code: 523