Follow-up of #2040 which changed the expected behavior for site builders/admins. Since it is likely to upset a portion of users (the ones that are using Backdrop to build and maintain sites - these are the ones we are trying to get to adopt Backdrop), it'd be best to follow up with a more solid/intuitive solution:
I think that when error messages are disabled, showing an error badge in the admin bar would be gold for site admins. We'd be putting existing, recently added functionality (badges) to good use and upsetting admins less with our choice of end-user-favoring defaults.
Recent comments
Tried and successfully applied DrAlbany's method with the form https://www.drupal.org/sandbox/grobot/2105379stickman hook. I also encountered the same situation. Thanks DrAlbany
Ubercart - Auto increment SKU
Since before migration you need to prepare the Drupal site - disabling and removing all modules, disabling themes, as part of the preparation you can clear the cache and logs, delete the search...
Trimming the size of my database for D2B_migrate not to error out (Request Entity Too Large / 504 Gateway Time-out)
QuickTabs is now available!!! But does not work as expected, already reported (https://github.com/backdrop-contrib/quicktabs/issues/14). Maybe an alternative solution using Views...
Quick Tabs (or method to simulate)