Fatal error after upgrade to WordPress 6.6.1

After upgrading to 6.6.1 I have fatal error.

Tried disabling all other plugins, changed theme, nothing works.

Only when I disable polylang fatal error is gone.

Log:

[13-Aug-2024 19:08:56 UTC] PHP Fatal error:  Uncaught TypeError: WP_Translation_Controller::set_locale(): Argument #1 ($locale) must be of type string, null given, called in /home/blog/public_html/wp-includes/l10n.php on line 803 and defined in /home/blog/public_html/wp-includes/l10n/class-wp-translation-controller.php:87
Stack trace:
#0 /home/blog/public_html/wp-includes/l10n.php(803): WP_Translation_Controller->set_locale()
#1 /home/blog/public_html/wp-content/plugins/polylang/include/olt-manager.php(106): load_textdomain()
#2 /home/blog/public_html/wp-includes/class-wp-hook.php(326): PLL_OLT_Manager->load_textdomains()
#3 /home/blog/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#4 /home/blog/public_html/wp-includes/plugin.php(517): WP_Hook->do_action()
#5 /home/blog/public_html/wp-content/plugins/polylang/frontend/choose-lang.php(112): do_action()
#6 /home/blog/public_html/wp-content/plugins/polylang/frontend/choose-lang-content.php(42): PLL_Choose_Lang->set_language()
#7 /home/blog/public_html/wp-content/plugins/polylang/frontend/choose-lang.php(217): PLL_Choose_Lang_Content->set_language()
#8 /home/blog/public_html/wp-content/plugins/polylang/frontend/choose-lang-content.php(121): PLL_Choose_Lang->home_language()
#9 /home/blog/public_html/wp-includes/class-wp-hook.php(324): PLL_Choose_Lang_Content->parse_main_query()
#10 /home/blog/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#11 /home/blog/public_html/wp-includes/plugin.php(565): WP_Hook->do_action()
#12 /home/blog/public_html/wp-includes/class-wp-query.php(1140): do_action_ref_array()
#13 /home/blog/public_html/wp-includes/class-wp-query.php(1868): WP_Query->parse_query()
#14 /home/blog/public_html/wp-includes/class-wp-query.php(3852): WP_Query->get_posts()
#15 /home/blog/public_html/wp-includes/class-wp.php(696): WP_Query->query()
#16 /home/blog/public_html/wp-includes/class-wp.php(816): WP->query_posts()
#17 /home/blog/public_html/wp-includes/functions.php(1336): WP->main()
#18 /home/blog/public_html/wp-blog-header.php(16): wp()
#19 /home/blog/public_html/index.php(17): require('/home/blog/...')
#20 {main}
  thrown in /home/blog/public_html/wp-includes/l10n/class-wp-translation-controller.php on line 87