No more working

On almost all sites from I can’t no more activate. Only on one page plugin is working properly ??

Fatal error:

`Fatal error: Uncaught TypeError: unlink(): Argument #2 ($context) must be of type resource or null, bool given in /var/www/vhosts/istok.de/vitarianer.com/wp-content/plugins/simple-cache/inc/class-sc-config.php:182 Stack trace: #0 /var/www/vhosts/istok.de/vitarianer.com/wp-content/plugins/simple-cache/inc/class-sc-config.php(182): unlink() #1 /var/www/vhosts/istok.de/vitarianer.com/wp-content/plugins/simple-cache/simple-cache.php(105): SC_Config->write() #2 /var/www/vhosts/istok.de/vitarianer.com/wp-includes/class-wp-hook.php(307): sc_activate() #3 /var/www/vhosts/istok.de/vitarianer.com/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters() #4 /var/www/vhosts/istok.de/vitarianer.com/wp-includes/plugin.php(476): WP_Hook->do_action() #5 /var/www/vhosts/istok.de/vitarianer.com/wp-admin/plugins.php(194): do_action() #6 {main} thrown in /var/www/vhosts/istok.de/vitarianer.com/wp-content/plugins/simple-cache/inc/class-sc-config.php on line 182

Btw: Black menu covers almost fully this support site ??