Can’t save email settings in admin

When i try and disable any of the emails in the admin, I get a server error.

All I’m doing is unticking the box for the pending email and then hitting save.

The site uses Oxygen Builder and I’ve substituted my real domain for “mydomain”

Error is server side and is

2824619#0: *60962 FastCGI sent in stderr: "PHP message: PHP Warning: copy(fake/ultimate-member/email/pending_email.php): Failed to open stream: No such file or directory in /var/www/vhosts/mydomain/httpdocs/wp-content/plugins/ultimate-member/includes/core/class-mail.php on line 579PHP message: PHP Warning: fopen(fake/ultimate-member/email/pending_email.php): Failed to open stream: No such file or directory in /var/www/vhosts/mydomain/httpdocs/wp-content/plugins/ultimate-member/includes/admin/core/class-admin-settings.php on line 3466PHP message: PHP Fatal error: Uncaught TypeError: fputs(): Argument #1 ($stream) must be of type resource, bool given in /var/www/vhosts/mydomain/httpdocs/wp-content/plugins/ultimate-member/includes/admin/core/class-admin-settings.php:3467
Stack trace:
#0 /var/www/vhosts/mydomain/httpdocs/wp-content/plugins/ultimate-member/includes/admin/core/class-admin-settings.php(3467): fputs()
#1 /var/www/vhosts/mydomain/httpdocs/wp-includes/class-wp-hook.php(307): um\admin\core\Admin_Settings->save_email_templates()
#2 /var/www/vhosts/mydomain/httpdocs/wp-includes/plugin.php(191): WP_Hook->apply_filters()
#3 /var/www/vhosts/mydomain/httpdocs/wp-content/plugins/ultimate-member/includes/admin/core/class-admin-settings.php(2214): apply_filters()
#4 /var/www/vhosts/mydomain/httpdocs/wp-includes/class-wp-hook.php(307): um\admin\core\Admin_Settings->save_settings_handler()
#5 /var/www/vhosts/mydomain/httpdocs/wp-includes/class-wp-hook.php(331): WP_Hook" while reading response header from upstream