Suddenly transactional letters stopped working

[imeow]

Greetings!
I have a problem. Transactional letters suddenly stopped working for me on my 1.5.1 MailWizz setup. The last letter was successfully sent at 6 AM (so probably nobody touched the configurations or code, etc).
Already tried all possible variants (db settings, switched delivery server type, flushing all possible caches).

Can somebody tell me ho to debug cron commands so I can take a look what is going on when I mailwizz trying to send the transactional letter?

Letters remain unsent in my DB for already a day.

 

[imeow]

In application log I have a messages like this:

in /usr/local/www/mailwizz/apps/common/models/DeliveryServer.php (2215)
in /usr/local/www/mailwizz/apps/common/models/DeliveryServer.php (964)
in /usr/local/www/mailwizz/apps/common/models/DeliveryServerSendgridWebApi.php (217)
2018/04/29 05:49:00 [error] [php] Illegal string offset 'value' (/usr/local/www/mailwizz/apps/common/models/DeliveryServer.php:2215)
Stack trace:
#0 /usr/local/www/mailwizz/apps/common/models/DeliveryServerSendgridWebApi.php(86): DeliveryServerSendgridWebApi->getParamsArray()
#1 /usr/local/www/mailwizz/apps/common/models/TransactionalEmail.php(233): DeliveryServerSendgridWebApi->sendEmail()
#2 /usr/local/www/mailwizz/apps/console/commands/SendTransactionalEmailsCommand.php(57): TransactionalEmail->send()
#3 /usr/local/www/mailwizz/apps/console/commands/SendTransactionalEmailsCommand.php(30): SendTransactionalEmailsCommand->process()
#4 unknown(0): SendTransactionalEmailsCommand->actionIndex()
#5 /usr/local/www/mailwizz/apps/common/framework/console/CConsoleCommand.php(172): ReflectionMethod->invokeArgs()
#6 /usr/local/www/mailwizz/apps/common/framework/console/CConsoleCommandRunner.php(71): SendTransactionalEmailsCommand->run()
#7 /usr/local/www/mailwizz/apps/common/framework/console/CConsoleApplication.php(92): CConsoleCommandRunner->run()
#8 /usr/local/www/mailwizz/apps/common/framework/base/CApplication.php(185): CConsoleApplication->processRequest()
#9 /usr/local/www/mailwizz/apps/init.php(239): CConsoleApplication->run()
#10 /usr/local/www/mailwizz/apps/console/console.php(28): require_once()

or like this:

2018/04/28 09:15:07 [error] [exception.CDbException] [82.196.11.148] SQLSTATE[HY000] [2002] No such file or directory
2018/04/28 09:15:07 [error] [exception.CDbException] [82.196.11.148] SQLSTATE[HY000] [2002] No such file or directory
2018/04/28 09:15:07 [error] [exception.CDbException] [82.196.11.148] exception 'CDbException' with message 'CDbConnection failed to open the DB connection.' in /usr/local/www/mailwizz/apps/common/framework/db/CDbConnection.php:405
Stack trace:
#0 /usr/local/www/mailwizz/apps/common/framework/db/CDbConnection.php(347): CDbConnection->open()
#1 /usr/local/www/mailwizz/apps/common/framework/db/CDbConnection.php(325): CDbConnection->setActive(true)
#2 /usr/local/www/mailwizz/apps/common/framework/base/CModule.php(394): CDbConnection->init()
#3 /usr/local/www/mailwizz/apps/common/framework/base/CModule.php(103): CModule->getComponent('db')
#4 /usr/local/www/mailwizz/apps/common/components/managers/OptionsManager.php(164): CModule->__get('db')
#5 /usr/local/www/mailwizz/apps/common/components/managers/OptionsManager.php(73): OptionsManager->loadCategory('system.common.s...')
#6 /usr/local/www/mailwizz/apps/common/components/init/SystemInit.php(48): OptionsManager->get('system.common.s...')
#7 /usr/local/www/mailwizz/apps/common/framework/base/CComponent.php(561): SystemInit->_runOnBeginRequest(Object(CEvent))
#8 /usr/local/www/mailwizz/apps/common/framework/base/CApplication.php(212): CComponent->raiseEvent('onBeginRequest', Object(CEvent))
#9 /usr/local/www/mailwizz/apps/common/framework/base/CApplication.php(183): CApplication->onBeginRequest(Object(CEvent))
#10 /usr/local/www/mailwizz/apps/init.php(238): CApplication->run()
#11 /usr/local/www/mailwizz/api/index.php(18): require_once('/usr/local/www/...')
#12 {main}
REQUEST_URI=/api/transactional-emails

 

[imeow]

I forgot to mention that I am using SendGrid as a delivery service for my DS.

 

[twisted1919]

@imeow - looks like you have an extension which mangles the email headers, or you added code to do so. If you did, try to remove that and see if things start working.