Learn to avoid the “Uncaught Error: Mismatched anonymous define() module” in Magento 2. Our Magento Support team is here to help you with your questions and concerns.

“Uncaught Error: Mismatched anonymous define() module” in Magento 2

According to our Experts, the “Uncaught Error: Mismatched anonymous define() module” is a common RequireJS error in Magento 2 and other JavaScript applications.

This error indicates a problem with module loading or definition, which is disrupting the application’s functionality.

Here is the error syntax:

Uncaught Error: Mismatched anonymous define() module: undefined
at makeError (require.js:5:1799)

This means that RequireJS cannot correctly match or identify an anonymous module during the script loading and dependency resolution process.

Impacts of This Error

• It prevents JavaScript modules from loading correctly.
• It breaks dependency management in the application.
• This error stops critical JavaScript functionality from executing.
• It interrupts script execution.
• It creates potential memory leaks.
• The error reduces overall application responsiveness.
• It may crash entire web application components.
• The error may cause inconsistent behavior across different browsers.
• Leads to partial or complete frontend rendering failures.
• It is problematic in complex web applications like Magento, Moodle, and Qlik Sense.
• It requires extensive debugging.
• The error may complicate module integration.
• It increases development time and complexity.
• It demands a thorough understanding of RequireJS configuration.
• The error also causes reduced application reliability.

Causes and Fixes

1. Duplicate Define Methods

Multiple `define()` calls for the same module without proper naming.

define('uniqueModuleName', ['dependencies'], function() {
// Module implementation
});
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2. Incorrect Module Loading Configuration

Misconfigured RequireJS configuration or module mapping.

requirejs.config({
baseUrl: '/scripts',
paths: {
'moduleAlias': 'path/to/actual/module'
},
shim: {
'legacy-module': {
deps: ['jquery'],
exports: 'LegacyModule'
}
}
});
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3. Third-Party JavaScript Interference

External scripts disrupt module loading.

({
baseUrl: './scripts',
name: 'main',
out: 'main-optimized.js',
optimize: 'uglify2'
})
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4. Minification and Build Process Issues

Incorrect JavaScript compilation or minification.

node r.js -o build.jsCopy Code

5. Loader Plugin Conflicts

Incompatible loader plugins or anonymous module usage.

define('moduleName', ['pluginName!resourcePath'], function(resource) {
// Module implementation
});
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6. Browser Caching and Script Loading

Incomplete or cached script loading.

requirejs.config({
urlArgs: "bust=" + (new Date()).getTime()
});
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Prevention Strategies

Our Experts have put together a few tips to prevent this error in the future:

• Always use named modules.
• Follow RequireJS best practices.
• Implement strict module naming conventions.
• Use RequireJS optimizer.
• Implement comprehensive build scripts.
• Validate module dependencies.
• Set breakpoints in `intakeDefines` function.
• Use browser developer tools.
• Log module loading information.
• Review JavaScript dependencies.
• Check for conflicting module definitions.
• Maintain a clean, organized module structure.

Quick Tips for Debugging

1. Use `grep -ir “define()”` to search for undefined modules.
2. Set breakpoints in the RequireJS loading mechanism.
3. Examine the specific script causing the error.
4. Verify module dependencies and configurations.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

Implementing the above fixes can prevent and resolve the “Mismatched anonymous define() module” error.

In brief, our Support Experts demonstrated how to avoid the “Uncaught Error: Mismatched anonymous define() module” in Magento 2