Fatal error: Array and string offset access syntax with curly braces is no longer supported in /customers/4/2/e/media-studio.se/httpd.www/wp-includes/blocks/index.php on line 2

Fatal error: Uncaught Error: Call to a member function set() on null in /customers/4/2/e/media-studio.se/httpd.www/wp-includes/l10n.php:856
Stack trace:
#0 /customers/4/2/e/media-studio.se/httpd.www/wp-includes/l10n.php(959): load_textdomain('default', '/customers/4/2/...', 'sv_SE')
#1 /customers/4/2/e/media-studio.se/httpd.www/wp-includes/class-wp-fatal-error-handler.php(49): load_default_textdomain()
#2 [internal function]: WP_Fatal_Error_Handler->handle()
#3 {main}
  thrown in /customers/4/2/e/media-studio.se/httpd.www/wp-includes/l10n.php on line 856