Ojs not loading and not opening pages

Our journal suddenly can not be opened any pages. At below I have attached screenshoot. Even we click any button just seem this page. Can you help me us? What should I do?


It looks like the theme for the site has been disabled.

What should we do? How can we enable the theme

It could also be a mistake in the CSS of the theme - for this you need to check the PHP error log.