If this type of error comes in Laravel then check your blade file for missing closing statements like @endsection or @endif etc. Usually happens because end statement is missing.

You can also check this StackOverflow for more information

https://stackoverflow.com/questions/23915853/laravel-error-ob-end-flush-failed-to-send-buffer-of-zlib-output-compression/69792437#69792437

But the answer that helped me, I found it on this

https://laracasts.com/discuss/channels/laravel/ob-end-flush-failed-to-send-buffer-of-zlib-output-compression-1