Summary

If GibbsCAM reports a Duplicate MDD or Duplicate VMM error during startup or when selecting a machine, the software has found two or more Machine Definition Database (MDD) or Virtual Machine Model (VMM) files with the same name or internal identifier.

This most commonly occurs when a custom MDD or VMM has been copied into multiple search locations or when an additional search path has been configured that contains duplicate files.

This article explains how to locate duplicate MDD and VMM files and remove the duplicates.

Table of Contents

Before You Begin

  • Close GibbsCAM before making changes to MDD or VMM files.

  • Administrator permissions may be required to modify files in the Program Files or ProgramData directories.

Symptoms

You may experience one or more of the following:

  • GibbsCAM displays a Duplicate MDD error.

  • GibbsCAM displays a Duplicate VMM error.

  • Duplicate machine definitions appear in machine selection lists.

  • Machine definitions fail to load correctly.

  • Unexpected machines appear after installing custom MDD or VMM files.

Procedure

Step 1 – Locate the All Users MDD or VMM Folder

Open GibbsCAM and navigate to:

Plug-ins > Pathfinder

Select one of the following:

  • All Users MDD Folder

  • All Users VMM Folder

The default locations are:

All Users MDD Folder

C:\ProgramData\Gibbs\GibbsCAM\<version>\MDD


All Users VMM Folder

C:\ProgramData\Gibbs\GibbsCAM\<version>\VMM


Review the contents for duplicate files.


Step 2 – Check the Default Installation Folder

From Plug-ins > Pathfinder, open:

  • MDD Folder

  • VMM Folder

The default installation folders are:

MDD Folder

C:\Program Files\Gibbs\GibbsCAM\<version>\MDD


VMM Folder

C:\Program Files\Gibbs\GibbsCAM\<version>\VMM


Compare the contents of these folders with the All Users folders.

Look for:

  • Duplicate filenames.

  • Copies of the same custom machine definition.

  • Older versions of custom files.


Step 3 – Check Additional Search Paths

Open:

File > Preferences > File

Locate the setting:

Additional VMM, MDD, Custom Drill Cycles...

If an additional folder has been configured:

  1. Browse to that folder.

  2. Check for duplicate MDD or VMM files.

  3. Remove duplicate copies or relocate them as appropriate.



Step 4 – Remove Duplicate Files

If duplicate files are found:

  1. Determine which copy is the correct version.

  2. Remove or relocate the duplicate copy.

  3. Ensure only one copy of each machine definition remains.

Important: Do not delete files unless you are certain they are duplicate copies. If unsure, make a backup before removing any files.


Step 5 – Restart GibbsCAM

After removing duplicate files:

  1. Close GibbsCAM if it is still running.

  2. Restart the application.

Verify that the duplicate error no longer appears.

Expected Result

GibbsCAM loads successfully and each machine definition is available only once without duplicate MDD or VMM errors.

Additional Information

MDD vs. VMM

  • MDD (Machine Definition Database) files define the machine configuration available within GibbsCAM.

  • VMM (Virtual Machine Model) files provide the associated machine models used by Machine Simulation.

Common Causes

Duplicate MDD or VMM errors are commonly caused by:

  • Copying custom machine files into multiple folders.

  • Installing updated machine definitions without removing older copies.

  • Configuring an additional search path that contains duplicate files.

  • Restoring machine files from backups without removing existing copies.

Best Practices

  • Maintain a single master copy of each custom MDD and VMM.

  • Avoid storing identical machine definitions in multiple search locations.

  • Document any custom machine installations.

  • Remove obsolete versions when updating custom machine files.

  • Back up custom MDD and VMM files before making changes.

Troubleshooting

  • Problem: Duplicate MDD or VMM errors continue after removing duplicate files.

Possible Causes

  • Additional search folders still contain duplicate files.

  • Multiple versions of the same machine definition remain.

Resolution

Review every configured MDD and VMM search location, including any additional folders configured under File > Preferences > File.


  • Problem: The duplicate file cannot be identified.

Possible Causes

  • Multiple versions have similar names.

  • Files were copied from backups or previous installations.

Resolution

Compare the contents of all configured MDD and VMM folders and remove redundant copies after verifying which version should be retained.


  • Problem: Machine definitions are missing after removing duplicates.

Possible Causes

  • The incorrect copy was removed.

Resolution

Restore the correct file from backup and ensure that only one active copy exists across all search locations.

  • The MDD Selected Does Not Match Your Security Options

  • General Crash Troubleshooting Guide

  • How to Reset GibbsCAM to the Default Settings

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Keywords

Duplicate MDD, Duplicate VMM, Machine Definition, Machine Definition Database, Virtual Machine Model, MDD Folder, VMM Folder, Additional VMM MDD Folder, Pathfinder, Machine Files, Custom Machines