Health Check Error: Found NULL values in moduleList strings

Overview

The Health Check wizard must be run when upgrading to evaluate whether your instance is suitable for upgrade. During the health check, various types of issues may be detected which can affect your ability to upgrade. This article will cover how to resolve a "Found NULL values in moduleList strings" error reported by the health check. 

Symptoms

This error generates an output similar to the following in health check:

Resolution

The generated error message will help determine the contents of the file causing the health check error. To address this issue, the line of code referencing the NULL values will need to be edited from Sugar before proceeding with the upgrade.

Update any files containing NULL values in the ./custom/Extension/application/Ext/Language/ directory.

Search the file mentioned in the error for any occurrences of NULL, then edit the line of code to remove the NULL value and replace it with a valid string instead.

For example, you may find a line of code similar to this:

 $app_list_strings['moduleList']['my_module'] = NULL;

The corrected line of code should then look similar to this:

 $app_list_strings['moduleList']['my_module'] = 'My Module';

Once the necessary change has been made, please navigate to Admin > Repair and perform a "Quick Repair and Rebuild" to ensure that the changes are recognized by the application. Then, perform the health check again to confirm that the error is no longer reported.