If the batch is not posted:

Correct the entries in the Journal Entry batch created from the Allocation.

OR

1. Delete the Journal Entry batch.
2. Correct the information in the Allocation Management pool or Allocation calculation.
3. Run the Allocation again to create a new batch.

If the batch is posted:

1. Reverse the original batch.
2. Post the reversal.
3. Choose to copy the original, posted batch as Regular if you are correcting the Journal Entry. You will be able to make changes to the copied, unposted batch.
4. Run the Allocation again to create a new batch if you are correcting the Allocation.