Approval Errors

Hello Kim, I have installed your plugin on my development site to complete the reviews before deploying. I have a recurring error when I approve a prayer that is currently showing as pending.
When a prayer is entered, it is set to default to pending. When I review and approve, the fault below is thrown. Also, If it is Approved and I Disapprove there is no error. If I re-approve the prayer, it once again throws the error below.
How do I fix this?

( ! ) Notice: Undefined index: filter_by in C:\Users\Cleve\Local Sites\learning-modules\app\public\wp-content\plugins\wp-prayer\core\class.tabular.php on line 2066
Call Stack
# Time Memory Function Location
1 0.0003 360688 {main}( ) …\admin.php:0
2 0.3454 4699456 do_action( ) …\admin.php:259
3 0.3454 4699728 WP_Hook->do_action( ) …\plugin.php:478
4 0.3454 4699728 WP_Hook->apply_filters( ) …\class-wp-hook.php:311
5 0.3455 4700544 WP_Prayer_Engine->processor( ) …\class-wp-hook.php:287
6 0.3458 4701800 wpe_Core_Controller->display( ) …\wp-prayer-engine.php:278
7 0.3458 4702872 include( ‘C:\Users\Cleve\Local Sites\learning-modules\app\public\wp-content\plugins\wp-prayer\modules\prayer\views\manage.php’ ) …\class.controller.php:63
8 0.3461 4712360 WPE_Prayer_Table->__construct( ) …\manage.php:206
9 0.3461 4712360 WPE_Prayer_Table->__construct( ) …\manage.php:5
10 0.3462 4714408 WPE_Prayer_Table->init_listing( ) …\class.tabular.php:538
11 0.3472 4727488 WPE_Prayer_Table->do_approve( ) …\class.tabular.php:598
12 0.3911 4710176 WPE_Prayer_Table->prepare_items( ) …\manage.php:135
13 0.3916 4710224 WPE_Prayer_Table->filter_query( ) …\class.tabular.php:1567