I've deleted your other post - new posters ave their first couple of posts moderated so they don't appear immediately.
Thanks for the report. It was my fault and I have responded to your ticket.

For anyone else bumping into this, on line 255 of /usr/clearos/apps/lets_encrypt/libraries/Lets_Encrypt.php, please change:

$shell->execute(self::COMMAND_CERTBOT, 'delete --cert-name ' . $name ' --max-log-backups ' . $this->max_logs, TRUE);

to:

$shell->execute(self::COMMAND_CERTBOT, 'delete --cert-name ' . $name . ' --max-log-backups ' . $this->max_logs, TRUE);

Then refresh the page.

I've just released 1.10.10 with a fix, but it may take up to a couple of hours to sync. Once it is in the mirror that your system uses, you will be able to update to it just with:

yum clean all && yum update app-lets-encrypt

It has already sync'd to the New York and San Francisco mirrors.

[edit]
Posts crossed.
Also I've tidied up the repeat posts.
[/edit]

Solved !
If you want to fix it your self today,. on line 255 of /usr/clearos/apps/lets_encrypt/libraries/Lets_Encrypt.php, please change:

$shell->execute(self::COMMAND_CERTBOT, 'delete --cert-name ' . $name ' --max-log-backups ' . $this->max_logs, TRUE);

to

$shell->execute(self::COMMAND_CERTBOT, 'delete --cert-name ' . $name . ' --max-log-backups ' . $this->max_logs, TRUE);