yii2 migration command gives warning how to fix it?

Question

I want to download and use thyseus/yii2-message. followed steps on github. for installation

1) $ composer require thyseus/yii2-message
2) $ php yii migrate/up --migrationPath=@vendor/thyseus/yii2-message/migrations

warning

PHP Warning:  Module 'openssl' already loaded in Unknown on line 0

Warning: Module 'openssl' already loaded in Unknown on line 0
Exception 'yiiaseInvalidConfigException' with message 'The configuration for
the "user" component must contain a "class" element.'

in C:xampphtdocsyii2-my-app2vendoryiisoftyii2diServiceLocator.php:204

Stack trace:
#0 C:xampphtdocsyii2-my-app2vendoryiisoftyii2diServiceLocator.php(260):
yiidiServiceLocator->set('user', Array)
#1 C:xampphtdocsyii2-my-app2vendoryiisoftyii2aseComponent.php(172): yii
diServiceLocator->setComponents(Array)
#2 C:xampphtdocsyii2-my-app2vendoryiisoftyii2BaseYii.php(529): yiiaseC
omponent->__set('components', Array)
#3 C:xampphtdocsyii2-my-app2vendoryiisoftyii2aseObject.php(105): yiiBa
seYii::configure(Object(yiiconsoleApplication), Array)
#4 C:xampphtdocsyii2-my-app2vendoryiisoftyii2aseApplication.php(205): y
iiaseObject->__construct(Array)
#5 C:xampphtdocsyii2-my-app2vendoryiisoftyii2consoleApplication.php(89):
 yiiaseApplication->__construct(Array)
#6 C:xampphtdocsyii2-my-app2yii(26): yiiconsoleApplication->__construct(Ar
ray)
#7 {main}
PHP Core Warning 'yiiaseErrorException' with message 'Module 'openssl' alread
y loaded'

in .Unknown:0

Stack trace:
#0 [internal function]: yiiaseErrorHandler->handleFatalError()
#1 {main}

1st command runs successfully but second command gives some warning I didnt get it? can anyone fix it? and I also want to know what does this migration command exactly do

Answer 1

For the warning, check answers to this question. For the error: Yii2-user or another user extension has to be installed first and working.