How to Downgrade Kernel on GNU/Linux Distros
GNU/Linux Downgrading Kernel Guide
How to Downgrade Kernel on GNU/Linux Distributions.
This procedure may be Necessary only if you want to Run some Software that is Not still supported from the Kernel.

$schemamarkup = get_post_meta(get_the_ID(), 'schemamarkup', true); if(!empty($schemamarkup)) { echo $schemamarkup; }
How to Downgrade Kernel on GNU/Linux Distributions.
This procedure may be Necessary only if you want to Run some Software that is Not still supported from the Kernel.