The Developer Mode Enabled is showing on the BuddyBoss Theme Options. See the screenshot below for your reference on how it looks like. 




Kindly be advised that if the Developer Mode Enabled is showing on the BuddyBoss Theme options, it means that the WP Debug mode is enabled in wp-config.php. 

Kindly check on your wp_config.php if the below code is showing: 

define( 'WP_DEBUG', true );

If it does, please change it to the below code. 

define( 'WP_DEBUG', false );

You can also check this by going to WordPress Dashboard - Tools - Site Health - Info tab - WordPress Constant. See the screenshot below for your reference.