You can use the Toolset Starter theme with Elementor, but only if you disable Layouts.
Or, if you must continue with Layouts on some pages and want to use Elementor for some static pages, then you could in a child theme add modified page templates for individual pages you want to design with Elementor.
Say you had a page with a slug of "landing", then you could duplicate the page.php template and call it page-landing.php.
Then edit it to remove the test for Layouts, like so:
The problem is that you are using the Toolset Starter Theme which has been deprecated for some time now and is no longer supported.
You can use Toolset and Elementor together with most themes, the list of recommended themes in particular, but Elementor doesn't work with the Toolset Starter Theme because it does not use the_content() to output the post content because the theme is designed specifically to work with Layouts and which uses an alternative to the_content() to render the post content.
Sorry, I tried to get the individual pages to work by editing the templates but when I tried I couldn't.
I understand that you are disappointed but it is not that Elementor is incompatible with Toolset, but it is incompatible with the Toolset Starter Theme, which is discontinued.