Seems to be the stylesheet it self, that is inaccessible.
It gives a warning of the following, when it tries to load it:
Refused to apply style from 'https://lms.vgck.edu.lk/theme/styles.php/classic/1605064707_1/all' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.
And when you try to open it, you just get:
It gives a warning of the following, when it tries to load it:
Refused to apply style from 'https://lms.vgck.edu.lk/theme/styles.php/classic/1605064707_1/all' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.
And when you try to open it, you just get:
It seems it is trying to load the styles from the classic theme, an not Boost.
You might want to check the rights of your moodle directories as it might be beacuse your web client is not allowed to access the files.