Reproduction of the fatal error below:
Go to '/admin/structure/ds/view_modes/manage', define a new view mode (one ore more entities, error-proof one-word title/description). 

Fatal error: Function name must be a string in /var/www/he/www/drupal8-spark/core/includes/form.inc on line 3873 Call Stack: 0.0001 333380 1. {main}() /var/www/he/www/drupal8-spark/index.php:0 0.0010 376544 2. drupal_handle_request() /var/www/he/www/drupal8-spark/index.php:12 0.3502 2205744 3. Symfony\Component\HttpKernel\Kernel->handle() /var/www/he/www/drupal8-spark/core/includes/bootstrap.inc:2004 0.3597 2265592 4. Drupal\Core\HttpKernel->handle() /var/www/he/www/drupal8-spark/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Kernel.php:197 0.3603 2260904 5. Symfony\Component\HttpKernel\HttpKernel->handle() /var/www/he/www/drupal8-spark/core/lib/Drupal/Core/HttpKernel.php:52 0.3604 2260904 6. Symfony\Component\HttpKernel\HttpKernel->handleRaw() /var/www/he/www/drupal8-spark/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php:73 0.7199 3422476 7. call_user_func_array() /var/www/he/www/drupal8-spark/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php:129 0.7199 3422792 8. Drupal\Core\HtmlFormController->content() /var/www/he/www/drupal8-spark/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php:0 0.7301 3441136 9. drupal_build_form() /var/www/he/www/drupal8-spark/core/lib/Drupal/Core/HtmlFormController.php:65 0.7868 3666344 10. drupal_process_form() /var/www/he/www/drupal8-spark/core/includes/form.inc:416 0.8176 3729780 11. drupal_validate_form() /var/www/he/www/drupal8-spark/core/includes/form.inc:908 0.8211 3730268 12. _form_validate() /var/www/he/www/drupal8-spark/core/includes/form.inc:1194 0.8224 3731760 13. _form_validate() /var/www/he/www/drupal8-spark/core/includes/form.inc:1356 0.8229 3732620 14. call_user_func_array() /var/www/he/www/drupal8-spark/core/includes/form.inc:1465 0.8230 3732656 15. form_validate_machine_name() /var/www/he/www/drupal8-spark/core/includes/form.inc:0

Comments

Blooniverse’s picture

Blooniverse commented

... btw, it doesn't matter how many DS sub-modules are on (i.e. form handling sub-module). The error occurs always.

swentel’s picture

swentel commented
Priority: Major » Normal

Yeah came after view mode conversion, needs work indeed :)

Blooniverse’s picture

Blooniverse commented

Good to hear! When do you think will you be able to put in some time? Can I help you with something?

swentel’s picture

swentel commented

Not sure when, probably in july somewhere during a sprint.

aspilicious’s picture

aspilicious commented
Title: Fatal error: Function name must be a string in ...drupal-root/core/includes/form.inc » Rip out view mode UI
Assigned: Unassigned » aspilicious
Issue tags: +sprint-ghent
aspilicious’s picture

aspilicious commented
Assigned: aspilicious » Unassigned
Status: Active » Fixed

Done by Swentel :)

Automatically closed -- issue fixed for 2 weeks with no activity.