How can I find out if the present theme version would work

Question

In the last years I've used pixture reloaded, a subtheme to adaptive theme, on some drupal sites and I was wondering whether this will work on Drupal 9. I've seen that the Adaptive theme homepage has not been reachable for some weeks and that the last update of Adaptive themes was 3 years ago. So I don't expect them to further develop the theme. How can I find out if the present version would work in Drupal 9?

Answer 1

Install the Upgrade Status module and then visit /admin/reports/upgrade-status and scan the Adaptive Theme and your sub-theme and get a report on all problems regarding Drupal 9 compatibility.

This module scans the code of the contributed and custom projects you have installed, and reports on any deprecated code that must be replaced before the next major version. Available project updates are also suggested to keep your site up to date as project will resolve deprecation errors over time.

Due to third party PHP library dependencies, the module needs to be installed with Composer.