and after activate it, the site become only html
it is not showing the theme
I am using Boost theme, I have tried to change the theme and purged all caches
untick slasharguments
but not of these solve the problem
I am running moodle 3.9

What is $CFG->wwwroot
set to in config.php
? This must match the URL you use in your browser to access the site, including the https: (or http:) part.
Open your browser's developer tools (for example: Network Monitor in Firefox) and reload the page. What do you see for CSS and JavaScript files? Do they load with status 200 (OK)? Or do they have some other status, for example 403 (Forbidden) or 404 (Not found)? If so, if you click on the request and view the response, is any error message shown?
500 means Internal Server Error. If you click on the request in your browser's developer tools is any error message shown in the request's response?
Find your web server's error logs. Can you see the 500 responses? Are there any relevant error messages?
Find the log file PHP writes errors to. Are there any error messages? If you don't know the location of PHP's error log try using a phpinfo file to find the error_log value.
Enable debugging in Moodle by adding these lines to config.php
. If this problem is caused by an error in Moodle debugging should show more details with error messages.
But the problem may be with your web server's – or PHP's – configuration.
(Edited by Mary Cooch to hide URL on request of OP - original submission Sunday, 21 May 2023, 11:17 AM)