If you are seeing that error, then your Steam account received a data transfer already, and is no longer eligible to transfer other data to. This generally occurs when an incorrect Battle.net account is linked duration the PC Move setup, causing a potentially empty Destiny account to be transferred. As the data migration is a single use per involved accounts, there is no option to reset, remove, or redo the transfer. Once an account has been involved in a transfer, that’s the one use. Your Bungie profile still shows your Battle.net account linked, with the character data in place. To migrate that data, you will now need to use an alternate Steam account, and then play the game on that alternate account. That means any paid expansions will need to be purchased on the alternate account as well, as Family Sharing on Steam is not supported for Destiny.

Bungie suggestion if thing does not transfer to do the transfer again following the guide. [url=https://www.bungie.net/7/en/PCMove]Here[/url] Read everything twice before proceeding to the next steps and take it slow.