PHP Fatal error: Uncaught ValueError: Unknown format specifier “D”

Hi there,

We have developed a multilanguage website for our client. It uses Polylang to support four different languages. The language switcher works for three languages, but when we change to Russian, there is a fatal error on the entire site:

PHP Fatal error:  Uncaught ValueError: Unknown format specifier "D" in /home/digiuwiu/restaurantbrodettoprzno.com/wp-content/plugins/restaurant-reservations/includes/Settings.class.php:661
Stack trace:
#0 /home/digiuwiu/restaurantbrodettoprzno.com/wp-content/plugins/restaurant-reservations/includes/Settings.class.php(661): sprintf()
#1 /home/digiuwiu/restaurantbrodettoprzno.com/wp-includes/class-wp-hook.php(324): rtbSettings->set_defaults()
#2 /home/digiuwiu/restaurantbrodettoprzno.com/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#3 /home/digiuwiu/restaurantbrodettoprzno.com/wp-includes/plugin.php(517): WP_Hook->do_action()
#4 /home/digiuwiu/restaurantbrodettoprzno.com/wp-settings.php(695): do_action()
#5 /home/digiuwiu/restaurantbrodettoprzno.com/wp-config.php(103): require_once('/home/digiuwiu/...')
#6 /home/digiuwiu/restaurantbrodettoprzno.com/wp-load.php(50): require_once('/home/digiuwiu/...')
#7 /home/digiuwiu/restaurantbrodettoprzno.com/wp-blog-header.php(13): require_once('/home/digiuwiu/...')
#8 /home/digiuwiu/restaurantbrodettoprzno.com/index.php(17): require('/home/digiuwiu/...')
#9 {main}
  thrown in /home/digiuwiu/restaurantbrodettoprzno.com/wp-content/plugins/restaurant-reservations/includes/Settings.class.php on line 661

We have narrowed done the source of the problem to your plugin. When your plugin is deactivated, everything works as expected and we can use the site in Russian. Can you please assist us with this problem?

Thank you

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