Errors installing into CiviCRM v5.17 and PHP 7.2/7.3

[peterm19]

Hi - Can anyone confirm if this extension should install onto above combination ? CiviCRM is running under Drupal 7 too. First attempt produced "dB Error" but new fields still appeared ok but none could be edited or filled in. After 2nd (or 3rd or 4th...) attempt, the "Eligible for Gift Aid ?" field couldn't be ticked or no menu appeared if it's an option group. I considered putting PHP back to v5.6 but then CiviCRM v5.17 threw an error. Before I resort to installing CiviCRM from scratch again, I'd appreciate knowing if it's just a version issue - our use of CiviCRM hinges on this :( Thanks.