Getting the same error on all versions after 3.27.1. Elementor said it was a plugin issue.
I went to the GITHUB page like the alert states and found this, which resolved my issue.
corzel commented 5 days ago
I fixed it adding:
session_write_close();
in lines 231 and 262 in this file: wp-content/plugins/unyson/framework/includes/hooks.php
229: session_start();
230: }
231: session_write_close();
232: }
