Fatal error: Uncaught Error: Call to undefined function wp_is_valid_utf8() in C:\inetpub\wwwroot\spinosi\wp-includes\formatting.php:2287
Stack trace:
#0 C:\inetpub\wwwroot\spinosi\wp-includes\class-wp-taxonomy.php(378): sanitize_title_with_dashes('category_name')
#1 C:\inetpub\wwwroot\spinosi\wp-includes\class-wp-taxonomy.php(290): WP_Taxonomy->set_props('post', Array)
#2 C:\inetpub\wwwroot\spinosi\wp-includes\taxonomy.php(532): WP_Taxonomy->__construct('category', 'post', Array)
#3 C:\inetpub\wwwroot\spinosi\wp-includes\taxonomy.php(63): register_taxonomy('category', 'post', Array)
#4 C:\inetpub\wwwroot\spinosi\wp-settings.php(513): create_initial_taxonomies()
#5 C:\inetpub\wwwroot\spinosi\wp-config.php(78): require_once('C:\\inetpub\\wwwr...')
#6 C:\inetpub\wwwroot\spinosi\wp-load.php(50): require_once('C:\\inetpub\\wwwr...')
#7 C:\inetpub\wwwroot\spinosi\wp-blog-header.php(13): require_once('C:\\inetpub\\wwwr...')
#8 C:\inetpub\wwwroot\index.php(17): require('C:\\inetpub\\wwwr...')
#9 {main}
thrown in C:\inetpub\wwwroot\spinosi\wp-includes\formatting.php on line 2287