PHP Errors, Huge Error Log

Hello, I’ve been ending up with a huge PHP error log, all with the same error. Took me a while to track down but WP Featherlight appears to be causing the errors:

call_user_func_array() expects parameter 1 to be a valid callback, function ‘false’ not found or invalid function name /website/wp-includes/class-wp-hook.php on line

Can anyone give me an idea on how I might fix this, probably a small mod in the WP Featherlight plugin files? Or perhaps Featherlight is interacting with another plugin. I don’t get any errors with Featherlight disabled.

I have a high traffic site and this is resulting in huge error log.