Title: Plugin Bootstrap File causes WSOD
Last modified: May 21, 2026

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# Plugin Bootstrap File causes WSOD

 *  [thehowarde](https://wordpress.org/support/users/thehowarde/)
 * (@thehowarde)
 * [1 week, 4 days ago](https://wordpress.org/support/topic/plugin-bootstrap-file-causes-wsod/)
 * Hi,
 * In `class-gst-woocommerce-addon.php`, there is a blank line before the opening
   <?php tag. This outputs whitespace before WordPress can send headers and causes
   errors like:
 * Cannot modify header information – headers already sent by (output started at…/
   wp-content/plugins/woo-gst/class-gst-woocommerce-addon.php:1)
 * On a client site this caused a blank white page, prevented admin/login from working
   properly, and also interfered with WooCommerce cart/session behavior.
 * I found this was already reported here about 6 months ago, and the reply said
   it would be removed in the next update:
   [https://wordpress.org/support/topic/issue-with-product-export-caused-by-blank-line-in-one-of-the-file/](https://wordpress.org/support/topic/issue-with-product-export-caused-by-blank-line-in-one-of-the-file/)
 * For now, I patched the file manually by removing the blank line before `<?php`,
   and the site started working again immediately.
 * Could you please release an update that removes the leading whitespace before
   the opening PHP tag in class-gst-woocommerce-addon.php?
    -  This topic was modified 1 week, 4 days ago by [thehowarde](https://wordpress.org/support/users/thehowarde/).
      Reason: Formatting

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 * 0 replies
 * 1 participant
 * Last reply from: [thehowarde](https://wordpress.org/support/users/thehowarde/)
 * Last activity: [1 week, 4 days ago](https://wordpress.org/support/topic/plugin-bootstrap-file-causes-wsod/)
 * Status: not resolved