Issues with php 8

Hi,

I received the following error message when trying to save changes I’d made to a user account on my site:

• Warning: Attempt to read property “filter” on null in /www/wp-content/plugins/gd-bbpress-tools/code/mods/signature.php on line 70 Fatal error: 
• Uncaught Error: Attempt to assign property “filter” on null in /www/wp-content/plugins/gd-bbpress-tools/code/mods/signature.php:71 Stack trace: #0 /wordpress/wp-includes/class-wp-hook.php(308): GDBTOModSignature->editor_form_profile(Object(WP_User)) #1 /wordpress/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #2 /wordpress/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #3 /wordpress/wp-admin/user-edit.php(847): do_action(‘edit_user_profi…’, Object(WP_User)) #4 {main} thrown in /www/wp-content/plugins/gd-bbpress-tools/code/mods/signature.php on line 71

When I first updated php to version 8, it wasn’t a problem but when I downgraded the php back to 7.4, the error message went away.

Please advise, thank you.