Cannot add new events

I recently upgraded an old site to the latest 2.8.34 version due to the webhost upgrading php & mysql. Everything was fine before but now I am unable to add a new event and receive the following error: Fatal error: Call to a member function return_instance() on boolean in /home/headwate/public_html/admin/core/lib/api/PerchAPI_Form.class.php on line 430

Following is the short diagnostic report:

Perch: 2.8.34, PHP: 5.6.32, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: 76b08b24596e12d4553bd41fc93cccd5bac2fe7a $, with PDO Server OS: Linux, cgi-fcgi Installed apps: content (2.8.34), assets (2.8.34), categories (2.8.34), perch_events (1.9), perch_blog (3.8.2) App runtimes: <?php include(PERCH_PATH.'/core/apps/content/runtime.php'); include(PERCH_PATH.'/addons/apps/perch_events/runtime.php'); ?> PERCH_LOGINPATH: /admin PERCH_PATH: /home/headwate/public_html/admin PERCH_CORE: /home/headwate/public_html/admin/core PERCH_RESFILEPATH: /home/headwate/public_html/admin/resources Image manipulation: GD Imagick PHP limits: Max upload 32M, Max POST 8M, Memory: 32M, Total max file upload: 8M F1: 6a33f95eca3667f9e0c39bf5ca2980fe Resource folder writeable: Yes DOCUMENT_ROOT: /home/headwate/public_html HTTP_HOST: headwaterslivestock.com REQUEST_URI: /admin/core/settings/diagnostics/ SCRIPT_NAME: /admin/core/settings/diagnostics/index.php

The changelog for the event app shows 1.9.1 adds compatibility for perch 2.8. How do I download this version? I am unable to upgrade to perch 3 for about a month as I don't have access to a development machine for testing and don't want to do this on a live site.

Thank you for your help.