"This Developer Name already exists or has been previously used" error when creating a Custom Tab
|Knowledge Article Number||000221104|
|Description||When trying to add a Custom Tab in a Developer Edition org, this error is encountered:
This Developer Name already exists or has been previously used. Please choose a different name.
|Resolution||If a managed Custom Tab for the same object has been deleted from a package under development, then you are unable to add a Custom Tab with the same name back to the org.
For additional information, see Deleting Components from Managed Packages