Installing 1.2 crashed Civi
I upgraded Minifier from 1.1 to 1.2 using the normal UI process, and Civi crashed with the solid 'Error' message. Looking in Drupal I saw this message 'Civi\Core\Exception\UnknownAssetException: Unrecognized asset name: crm.payment.js in Civi\Core\AssetBuilder->render() (line 217 of /home/anawimin/public_html/sites/all/modules/civicrm/Civi/Core/AssetBuilder.php)'. Also, just before this was this message 'Warning: rmdir(/home/anawimin/public_html/sites/default/ext/minifier): Directory not empty in CRM_Utils_File::cleanDir() (line 149 of /home/anawimin/public_html/sites/all/modules/civicrm/CRM/Utils/File.php).' To get Civi back I replaced the 1.2 code (which only had the 'Vendor' folder) with the 1.1 code. This got Civi going again after clearing caches.