zlib Output Compression
Notice: ob_end_flush(): failed to send buffer of zlib output compression (0)
If you encounter this error, it means your server doesn't have the PHP zLib extension enabled. Contact your web host provider and ask them to enable it for you.
If you manage the server yourself, you can modify the zlib.output_compression setting in your server php.ini file, such as zlib.output_compression = On
.