Oracle encryption wallet 12c I exported a database to a transportable tablespace and send the data to a customer.  They received the error: ORA-28365 Wallet is not open.
Do I need to close the wallet before creating the export?  Is there something on the customer's end that they can do to allow them to import this data?

Haven't had this problem with any other customer since switching to 12c in the last 6 months so this is strange to me that this is the only customer having this problem?

Thanks for any insight!
For TDE:

Do transportable tablespaces work with TDE tablespace encryption?


  Yes, but it requires that the wallet containing the master key is
  copied to the secondary database. If the tablespace is moved and the
  master key is not available, the secondary database will return an
  error when the data in the tablespace is accessed.


How to use TTS With TDE (Doc ID 1674166.1)


  ... Only difference when transporting tablespace using TDE is the
  wallet needs to copied to the target database. ...