Null pointer when upgrading to woo 5.0

Hi,
I’m getting a null pointer on my staging when upgrading to woo 5.0.
Trace below.

Fatal error: Uncaught Error: Call to undefined function wc_string_to_bool() in /home/deb130999/domains/staging.nl/public_html/wp-content/plugins/woo-variation-swatches/includes/functions.php:2011 Stack trace: #0 /home/deb130999/domains/staging.nl/public_html/wp-includes/class-wp-hook.php(287): wvs_defer_script_load(‘<script src=’ht…’, ‘jquery-core’, ‘https://staging…&#8217;) #1 /home/deb130999/domains/staging.nl/public_html/wp-includes/plugin.php(212): WP_Hook->apply_filters(‘<script src=’ht…’, Array) #2 /home/deb130999/domains/staging.nl/public_html/wp-includes/class.wp-scripts.php(400): apply_filters(‘script_loader_t…’, ‘<script src=’ht…’, ‘jquery-core’, ‘https://staging…&#8217;) #3 /home/deb130999/domains/staging.nl/public_html/wp-includes/class.wp-dependencies.php(116): WP_Scripts->do_item(‘jquery-core’, 0) #4 /home/deb130999/domains/staging.nl/public_html/wp-includes/class.wp-scripts.php(643): WP_Dependencies->do_items(Array, 0) #5 /home/deb130999/domains/staging.nl/public_html/wp-includes in /home/deb130999/domains/staging.nl/public_html/wp-content/plugins/woo-variation-swatches/includes/functions.php on line 2011