salmansaleem920

search for ssl plugin and activate it

in your core wordpress files, there is php file that goes by the name of function.
search this code
<?php preview_theme() ?>
there is some anomaly in this preview_theme() as far as i can guess by some backdoor malware or hacker

bug in edge because i cant access developer tools as well to detect the problem

if your are using cloudflare or other ssl services where dns needs to be setup for subdomain to come alive, please check that else subdomain issue can only be solved from the hosting provider

through command line or the best way is to git bash to give folder permission
install git if you dont have it
go to your htdocs folder
run gitbash as administrator and navigate to htdocs
and execute this command
ls chmod 777

go to your database from phpMyadmin
run this query
UPDATE wp_options SET option_value = ” WHERE option_name = ‘active_plugins’;
Upon execution, this query will clear the active_plugins field of all active plugins, effectively disabling (without uninstalling or modifying) the entire set. This method is great if you plan to re-enable each plugin individually, after resolving issues with the website.
this will let u login back in your dashboard

Open the page in incognito mode in chrome and see the performance. if same issue occurs, i bet the problem is with cache plugin that is minifying your css or js files in hope of increasing page speed

@jnashhawkins is right

There can be two obvious reasons!
1) Plugin Conflicting with theme
2) Theme crash due to changes in its files
How To Debug ?
Go to wp-config file directly from cpanel or plesk or from hosting platform.
Scroll down and you will see this code below
define( ‘WP_DEBUG’, false );
change the value from false to ‘true’. By default it is false so that customers or user’s dont see the error screen
Once that is done, refresh the page and you can see the error
If its plugin conflict, go to your database by phpmyadmin
Run this query in your database

UPDATE wp_options SET option_value = ” WHERE option_name = ‘active_plugins’;

Upon execution, this query will clear the active_plugins field of all active plugins, effectively disabling (without uninstalling or modifying) the entire set. This method is great if you plan to re-enable each plugin individually, after resolving issues with the website.