error on line 170 of file wp-content/plugins/kirki/packages/kirki-framework/

The latest update has broken the site and we are getting the following error:

Your PHP code changes were rolled back due to an error on line 170 of file wp-content/plugins/kirki/packages/kirki-framework/module-css/src/CSS/Generator.php. Please fix and try saving again.

Uncaught Error: Class "\Kirki\Field\CSS\ReactColorful" not found in wp-content/plugins/kirki/packages/kirki-framework/module-css/src/CSS/Generator.php:170
Stack trace:
#0 wp-content/plugins/kirki/packages/kirki-framework/module-css/src/CSS.php(351): Kirki\Module\CSS\Generator::css()
#1 wp-content/plugins/kirki/packages/kirki-framework/module-css/src/CSS.php(268): Kirki\Module\CSS::loop_controls()
#2 wp-content/plugins/kirki/packages/kirki-framework/module-css/src/CSS.php(179): Kirki\Module\CSS->print_styles()