Power BI Desktop Copy or Duplicate Object now fails

Hi Michaeldias 

 This is AI generated and unvalidated but I hope it helps:

 Issue Summary

You're encountering a System.ArgumentException in Power BI Desktop (version 2.146.705.0, August 2025 release) when attempting to duplicate a query. The error message:

"Item has already been added. Key in dictionary: 'Interface_Change_Log'"

...indicates that Power BI is trying to add a query with a name that already exists in the internal dictionary, causing a conflict.

🧩 Known Issue

This is a known issue affecting multiple users, especially when duplicating queries or working with models that have previously been saved with certain naming conventions . It can lead to corrupted PBIX files that fail to open later.

✅ Workarounds

Until Microsoft releases a fix, here are some recommended workarounds:

1. Avoid using the Duplicate option directly:

   • Instead, create a blank query and manually copy the M code from the original query using the Advanced Editor .

2. Check for duplicate query names:

   • Even if names look unique, Power BI may treat them as duplicates due to internal metadata conflicts. Renaming queries before duplication might help.

3. Use version control manually:

   • Save incremental versions of your PBIX file (e.g., Model_v1.pbix, Model_v2.pbix) to avoid losing hours of work if corruption occurs.

4. Avoid syncing with OneDrive or cloud folders during development:

   • Some users reported fewer issues when working locally rather than in synced folders .

🛠️ Fix Status

As of now, no official fix has been listed in the Power BI Desktop change log 

 or the Known Issues page 

 for the August 2025 release. However, Microsoft is aware of similar issues and has addressed related bugs in previous updates.