SAP Message AC684 - You cannot create transaction type &1 manually.

Diagnosis
You want to create transaction type &V1&. However, the key for thistransaction type is not allowed, since transaction types 'Ixx', 'Jxx'(xx = 00 - 99) and 'QKI' are automatically created by the system.

Procedure
Enter a different key for the new transaction type.