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Oct 28, 2026 5:17 AM UTC

KB-2425 APNX-1-4104-000 DuplicateFunctionsException When Upgrading or Installing a Plugin Due to a Function Conflict

Symptoms

1. When attempting to deploy or upgrade a plugin via the Admin Console > Plug-ins > ADD NEW PLUG-INS > Appian AppMarket Plug-ins, the plugin fails to deploy and a red banner shows the following message:

Deployment failed for all plugins. Please review the logs and retry the operation.

2. When attempting to deploy the plugin jar file via Admin Console > Plug-ins > ADD NEW PLUG-INS > Direct Upload, the following error shows up:

Plug-in failed to deploy.Error: There was a problem loading the module descriptor: <FunctionName> .<br/>com.appiancorp.process.expression.DuplicateFunctionsException: The following function(s) are already registered in the system: <FunctionName> (APNX-1-4104-000)

Cause

Two deployed plugins cannot contain the same function. The error occurs because the plugin being installed or upgraded contains a function that is already registered in the system by another deployed plugin. Appian cannot resolve duplicate function definitions across plugins, resulting in the DuplicateFunctionsException error.

Action

  1. Identify the duplicate function name referenced in the error message (the function listed after The following function(s) are already registered in the system:).
  2. Navigate to Admin Console > Plugins.
  3. Review the list of installed plugins and identify the other plugin that already registers the same function. (If you are unsure which plugin provides the function, check each plugin's documentation on the AppMarket, or review the plugin's registered functions.)
  4. Determine whether the other plugin is still required in your environment:
  5. If the other plugin is no longer needed, uninstall it, then retry installing or upgrading the target plugin.
  6. If the other plugin is still needed, you cannot have both plugins deployed simultaneously while they share the same function. Evaluate which plugin provides the functionality you require and deploy only that one, or contact the plugin owner/Appian Support to discuss alternatives.
  7. Retry installing or upgrading the target plugin.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: October 2026

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