Anytime I run this to install any extension:
php bin/magento setup:upgrade.
I get the error -

connection "developer" is not defined.

I have tried to change the mode to developer and when I run it, the same issue comes out. this has reduced my ability to install new apps.

How do I resolve this?

6 Answers 6


After taking pull from git for a running projec, I forgot to put env.php in app/etc dir, and I faced same issue. Check if env.php is there and set the connection for default_setup is "default or developer" as per you deploy mode.


I faced the same problem when I tried to install Magento in production mode. So I switched to developer mode, installed Magento and than switched to production and this helped. Magento version is 2.4.3


env.php just changed 'connection' => 'default'

Fixed :-)


As i have checked in env.php there was issue under 'resource' => [ 'default_setup' => [ 'connection' => 'default' ] ],

Connection was developer.


Check if the env.php file exists in the app/etc folder. If it's there, check whether the values present are correct or not


found a way out.. i went to the app/etc/local.xml

and changed the connection to default and mode to default..

worked out well for me

  • You may mark your answer as accepted if it worked for you.
    – Mac
    Commented Mar 15, 2019 at 12:35

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