If you've come across the error 'Argument passed to __construct() must implement interface Magento\Framework\DB\Adapter\AdapterInterface or be null' while working with tables in your custom Magento 2.4.1 module, fear not.

This article is here to assist you in resolving and troubleshooting this issue.

Understanding the Error

When accessing table contents in your custom module, you may encounter the error 'Type Error occurred when creating object: ... must implement interface Magento\Framework\DB\Adapter\AdapterInterface or be null.' It's important to note that this error is unique to production mode and does not arise in developer mode.

The source of the error lies within the Collection class (collection.php).

By scrutinizing the code in this class, you can pinpoint where the implementation of Magento\Framework\DB\Adapter\AdapterInterface is erroneous or missing.

Distinguishing between production and developer modes is crucial whilst troubleshooting this issue.

A thorough analysis of the code and configuration disparities between the two modes is necessary to uncover the root cause of the error.

Identifying the root cause leads to resolving the error by rectifying the deficient or erroneous implementation of Magento\Framework\DB\Adapter\AdapterInterface in the collection class.

This may require making adjustments to the code or configuration to ensure compatibility with the interface.