[2019-05-16 14:30:02] production.ERROR: Only mailables may be queued. {"exception":"[object] (InvalidArgumentException(code: 0): Only mailables may be queued.
 at /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Mail/Mailer.php:367)
[stacktrace]
#0 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Support/Facades/Facade.php(221): Illuminate\\Mail\\Mailer->queue('emails.duty_rem...
', Array, Object(Closure))
#1 /home/msft-duty/msft-intern-15/app/Console/Commands/SendReminderEmail.php(57): Illuminate\\Support\\Facades\\Facade::__callStatic('queue', Array)
#2 [internal function]: App\\Console\\Commands\\SendReminderEmail->handle()
#3 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php(29): call_user_func_array(Array, Array)
#4 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php(87): Illuminate\\Container\\BoundMethod::Illuminate\\Conta
iner\\{closure}()
#5 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php(31): Illuminate\\Container\\BoundMethod::callBoundMethod(O
bject(Illuminate\\Foundation\\Application), Array, Object(Closure))
#6 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Container/Container.php(564): Illuminate\\Container\\BoundMethod::call(Object(Illumi
nate\\Foundation\\Application), Array, Array, NULL)
#7 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Console/Command.php(184): Illuminate\\Container\\Container->call(Array)
#8 /home/msft-duty/msft-intern-15/vendor/symfony/console/Command/Command.php(251): Illuminate\\Console\\Command->execute(Object(Symfony\\Component\\Console\\I
nput\\ArgvInput), Object(Illuminate\\Console\\OutputStyle))
#9 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Console/Command.php(171): Symfony\\Component\\Console\\Command\\Command->run(Object(
Symfony\\Component\\Console\\Input\\ArgvInput), Object(Illuminate\\Console\\OutputStyle))
#10 /home/msft-duty/msft-intern-15/vendor/symfony/console/Application.php(886): Illuminate\\Console\\Command->run(Object(Symfony\\Component\\Console\\Input\\A
rgvInput), Object(Symfony\\Component\\Console\\Output\\ConsoleOutput))
#11 /home/msft-duty/msft-intern-15/vendor/symfony/console/Application.php(262): Symfony\\Component\\Console\\Application->doRunCommand(Object(App\\Console\\Co
mmands\\SendReminderEmail), Object(Symfony\\Component\\Console\\Input\\ArgvInput), Object(Symfony\\Component\\Console\\Output\\ConsoleOutput))
#12 /home/msft-duty/msft-intern-15/vendor/symfony/console/Application.php(145): Symfony\\Component\\Console\\Application->doRun(Object(Symfony\\Component\\Con
sole\\Input\\ArgvInput), Object(Symfony\\Component\\Console\\Output\\ConsoleOutput))
#13 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Console/Application.php(89): Symfony\\Component\\Console\\Application->run(Object(S
ymfony\\Component\\Console\\Input\\ArgvInput), Object(Symfony\\Component\\Console\\Output\\ConsoleOutput))
#14 /home/msft-duty/msft-intern-15/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php(122): Illuminate\\Console\\Application->run(Object(Sy
mfony\\Component\\Console\\Input\\ArgvInput), Object(Symfony\\Component\\Console\\Output\\ConsoleOutput))
#15 /home/msft-duty/msft-intern-15/artisan(37): Illuminate\\Foundation\\Console\\Kernel->handle(Object(Symfony\\Component\\Console\\Input\\ArgvInput), Object(
Symfony\\Component\\Console\\Output\\ConsoleOutput))
#16 {main}
"} {"user_id":"anonymous","uid":"8d9b2c0b440c2dc98c222ea89e9fa554"}