Fatal error in Css_Customizer.php

Greetings. Since the 2.0 release we’re getting fatal errors in the Tooltip Preview iframe that appear to be related to passing an empty Array into the second parameter of the generate_css_selector() function. See below…

When seeking help with this issue, you may be asked for some of the following information:
WordPress version 5.6
Current theme: (version )
Current plugin: Glossary (Premium) (version 2.0)
PHP version 7.3.25

Error Details
=============
An error of type E_ERROR was caused in line 235 of the file /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/frontend/Css_Customizer.php. Error message: Uncaught TypeError: Argument 2 passed to Glossary\Frontend\Css_Customizer::generate_css_proprierty() must be of the type string, null given, called in /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/frontend/Css_Customizer.php on line 216 and defined in /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/frontend/Css_Customizer.php:235
Stack trace:
#0 /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/frontend/Css_Customizer.php(216): Glossary\Frontend\Css_Customizer->generate_css_proprierty(‘color’, NULL)
#1 /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/frontend/Css_Customizer.php(87): Glossary\Frontend\Css_Customizer->generate_css_selector(‘.glossary-toolt…’, Array)
#2 /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/backend/views/preview.php(93): Glossary\Frontend\Css_Customizer->print_css()
#3 /srv/htdocs/wp-content/plugins/glossary-by-codeat-premium/backend/Settings_Page.php(86): include_once(‘/srv/htdocs/wp-…’)
#4 /wordpress/core/5.6/wp-includes/class-wp-hook.php(287): Glossary\Backend\Settings_Page->preview__premium_only(”)
#5 /wordpress/core/5.6/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(NULL, Array)
#6 /wordpress/core/5.6/wp-includes/plugin.php(484): WP_Hook->do_action(Array)
#7 /wordpress/core/5.6/wp-settings.php(557): do_action(‘init’)
#8 /srv/htdocs/wp-config.php(92): require_once(‘/wordpress/core…’)
#9 /wordpress/core/5.6/wp-load.php(42): require_once(‘/srv/htdocs/wp-…’)
#10 /wordpress/core/5.6/wp-admin/admin.php(34): require_once(‘/wordpress/core…’)
#11 /wordpress/core/5.6/wp-admin/index.php(10): require_once(‘/wordpress/core…’)
#12 {main}
thrown