aniketsarthi

hii,
I am using Slick Contact Forms plugin but email are not send they show Error. Please try again. I check and uncheck wp_mail() option. both are tried but not help.
My site https://onvacation.biz.

Tried to activate this plugin and immediately got a fatal error to an undefined function in my backend
Fatal error: Call to undefined function Nette\Utils\mb_strtoupper() in /wp-content/plugins/simple-subscribe/libs/Nette/Nette.min.php on line 7191

I am reinstall plugin but cant process