Fatal Error: Class "um_ext\um_polylang\core\Fields" not found

[veerap000]

When activating this plugin I'm getting

Fatal error: Uncaught Error: Class "um_ext\um_polylang\core\Fields" not found in [path-to-local-install]/wp-content/plugins/um-polylang-main/includes/core/class-um-polylang.php:61

Stack trace:

#0 [path-to-local-install]/wp-content/plugins/um-polylang-main/includes/core/class-um-polylang.php(46): UM_Polylang->fields()
#1 [path-to-local-install]/wp-content/plugins/um-polylang-main/includes/core/class-um-polylang.php(35): UM_Polylang->__construct()
#2 [path-to-local-install]/wp-content/plugins/ultimate-member/includes/class-init.php(153): UM_Polylang::instance()
#3 [path-to-local-install]/wp-content/plugins/um-polylang-main/um-polylang.php(78): UM->set_class('Polylang', true)
#4 [path-to-local-install]/wp-includes/class-wp-hook.php(310): um_polylang_init('')
#5 [path-to-local-install]/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters(NULL, Array)
#6 [path-to-local-install]/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#7 [path-to-local-install]/wp-settings.php(495): do_action('plugins_loaded')
#8[path-to-local-install]/wp-config.php(110): require_once('/Users/...')
#9 [path-to-local-install]/wp-load.php(50): require_once('/Users/...')
#10 [path-to-local-install]/wp-blog-header.php(13): require_once('/Users/...')
#11 [path-to-local-install]/index.php(17): require('/Users/...')
#12 {main}
  thrown in [path-to-local-install]/wp-content/plugins/um-polylang-main/includes/core/class-um-polylang.php on line 61

How to reproduce:

• LocalWP with fresh WordPress install (PHP 8.1.9, WordPress 6.3.1, nginx, MySQL 8.0)
• Polylang 3.4.5 (latest) with two languages installed (English + Spain)
• Ultimate Member 2.6.11 (latest) installed (no changes to any setting, created only the login, registration, user, etc. pages with automated "Create pages" button that plugin provided)
• Installed latest version of this plugin -> fatal error comes on activation