Demo Website not working

Hi, I just installed the plugin and I’m trying to learn how to use it. I was trying to see the demo site, but when I try to login, I get:

“The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.” (https://maxicharts.com/wp-login.php)

If I go to https://maxicharts.com/all-shortcode-parameters/

I get:
“The site is experiencing technical difficulties.”

can you take a look, please.

Thank you.