I was changing a value in my custom CSS and received the following error message:
Warning: unlink(/home/content/76/9554076/html/oncoursetest/wp-content/uploads/bb-theme/customizer-55d86ff5b82a2.css) [function.unlink]: No such file or directory in /home/content/76/9554076/html/oncoursetest/wp-content/themes/bb-theme/classes/class-fl-customizer.php on line 701