Toolset provides View and Form widgets in the Elementor UI, but this is producing PHP deprecation notices in debug logs, like so:
PHP Deprecated: _register_controls is deprecated since version 3.1.0! Use Elementor\Controls_Stack::register_controls() instead. in ...wp-includes/functions.php on line 5323
The notices do not affect functionality.
The issue will be fixed in a future release of Views and Blocks.
In the meantime you can apply a patch to remove the notices.
Download and unzip this archive which contains two php files.
Overwrite the existing view.php file at wp-views/… or toolset-blocks/vendor/toolset/toolset-common/inc/autoloaded/interop/handler/elementor/widgets/view/view.php
and overwrite the existing form.php file at wp-views/… or toolset-blocks/vendor/toolset/toolset-common/inc/autoloaded/interop/handler/elementor/widgets/form/form.php