500 Internal Server Error

compact(): Undefined variable: operator (8)

#0 [internal function]: flight\Engine->handleError(8, 'compact(): Unde...', '/home1/sonicloc...', 873, Array)
#1 /home1/sonicloc/public_html/vendor/illuminate/database/Query/Builder.php(873): compact('type', 'operator', 'query', 'boolean')
#2 [internal function]: Illuminate\Database\Query\Builder->addWhereExistsQuery(Object(Illuminate\Database\Query\Builder), 'and', false)
#3 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(1419): call_user_func_array(Array, Array)
#4 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(937): Illuminate\Database\Eloquent\Builder->__call('addWhereExistsQ...', Array)
#5 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(822): Illuminate\Database\Eloquent\Builder->addHasWhere(Object(Illuminate\Database\Eloquent\Builder), Object(Illuminate\Database\Eloquent\Relations\BelongsTo), '>=', 1, 'and')
#6 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(878): Illuminate\Database\Eloquent\Builder->has(Object(Illuminate\Database\Eloquent\Relations\BelongsTo), '>=', 1, 'and', Object(Closure))
#7 /home1/sonicloc/public_html/vendor/jgrossi/corcel/src/PostBuilder.php(63): Illuminate\Database\Eloquent\Builder->whereHas('term', Object(Closure))
#8 [internal function]: Corcel\PostBuilder->Corcel\{closure}(Object(Corcel\TermTaxonomyBuilder))
#9 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(1179): call_user_func_array(Object(Closure), Array)
#10 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(818): Illuminate\Database\Eloquent\Builder->callScope(Object(Closure))
#11 /home1/sonicloc/public_html/vendor/illuminate/database/Eloquent/Builder.php(878): Illuminate\Database\Eloquent\Builder->has(Object(Illuminate\Database\Eloquent\Relations\BelongsToMany), '>=', 1, 'and', Object(Closure))
#12 /home1/sonicloc/public_html/vendor/jgrossi/corcel/src/PostBuilder.php(64): Illuminate\Database\Eloquent\Builder->whereHas('taxonomies', Object(Closure))
#13 /home1/sonicloc/public_html/App/controllers/BlogController.php(169): Corcel\PostBuilder->taxonomy('post_tag', 'car-keys')
#14 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/core/Dispatcher.php(201): BlogController::tag('car-keys')
#15 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/core/Dispatcher.php(142): flight\core\Dispatcher::invokeMethod(Array, Array)
#16 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/Engine.php(311): flight\core\Dispatcher::execute(Array, Array)
#17 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/core/Dispatcher.php(196): flight\Engine->_start()
#18 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/core/Dispatcher.php(142): flight\core\Dispatcher::invokeMethod(Array, Array)
#19 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/core/Dispatcher.php(48): flight\core\Dispatcher::execute(Array, Array)
#20 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/Engine.php(64): flight\core\Dispatcher->run('start', Array)
#21 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/core/Dispatcher.php(196): flight\Engine->__call('start', Array)
#22 /home1/sonicloc/public_html/vendor/mikecao/flight/flight/Flight.php(76): flight\core\Dispatcher::invokeMethod(Array, Array)
#23 /home1/sonicloc/public_html/index.php(11): Flight::__callStatic('start', Array)
#24 {main}