PROBLEM

It may happen that when you create a new edition from an old one with many articles, that Fred fails to save masters and gives an exception:

System.ArgumentException: An item with the same key has already been added.

   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)

   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)

   at EdtDoc.SaveNew(ArtCopierDlg copydlg)

   at EdtDoc.Save(Boolean showArtCoptDlg, String[] CopyArtParams)

   at EdtDoc.Save()

   at TeraDP.GN4.AddIns.EditionDesignerAddIn.Save()

   at (Object , Object[] )

   at TeraDP.GN4.WinUI.AddInManagerBase.ExecuteCommand(String commandName, Boolean displayMessage, Object[] parameters)

CAUSE

The possible reason are the duplicates of thumbnails in the masters. It was caused by a bug, fixed in 1.6. However, the duplicated thumbnails must be cleaned manually.

SOLUTION

To clean duplicated thumbnails of the masters, see the instructions in Troubleshooting masters, paragraph "An item with the same key has already been added".