Mercury Editor enabling for content types error

Problem/Motivation

Trying to enable Mercury Editor for content types, but when we go to create new content after configuring, we get the following error.

The website encountered an unexpected error. Try again later.

TypeError: Drupal\workspaces\Controller\WorkspacesHtmlEntityFormController::getContentResult(): Return value must be of type array, Symfony\Component\HttpFoundation\RedirectResponse returned in Drupal\workspaces\Controller\WorkspacesHtmlEntityFormController->getContentResult() (line 80 of core/modules/workspaces/src/Controller/WorkspacesHtmlEntityFormController.php).

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes