Question:

How to Resolve a Duplicate Custom Key in Network? 

Answer:

Network checks to ensure that any given custom key is only active on one record at a time. If attempting to add a duplicate into the system, a duplicate custom key error is thrown detailing on which record the active key already exists. To resolve: navigate to the record referenced in the error and inactivate the custom key. Once completed, adding the custom key to another record is now allowed.

To resolve:

1. Navigate to the record referenced in the error.
2. Inactivate the custom key. 

Once completed, adding the custom key to another record is now allowed.

Related Documentation:

KB Article: How to Troubleshoot a "DCR Job was unable to apply changes" Inbox Error in Network?

Thank you