Error: An item with the same key has already been added" when trying to edit import process after mapping ISPRIMARY fields for collection fields"

When tyring to edit an import process in which ISPRIMARY was mapped for collection fields such as Addresses and Phones, error: "An item with the same key has already been added"
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch. 

Environment

 2.91.1535.61
 2.91.1535, patch 64

Was this article helpful?