Fatal Error When Activating Collapsing Categories Plugin

Hi,

I’m experiencing a fatal error when trying to activate the Collapsing Categories plugin on my WordPress site. The error message I receive is:

Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class CollapsCat does not have a method "init" in /wp-includes/class-wp-hook.php:324 Stack trace: #0 /wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array) #1 /wp-includes/plugin.php(517): WP_Hook->do_action(Array) #2 /wp-admin/plugins.php(196): do_action('activate_collap...') #3 {main} thrown in /wp-includes/class-wp-hook.php on line 324

It seems like the plugin is trying to call an init method in the CollapsCat class, but that method doesn’t exist.

I have tried reinstalling the plugin, disabling other plugins, and checking for conflicts, but the issue persists. Could you please provide guidance on how to fix this?

Thanks in advance!

Best regards,