In the Payment Application (08.030) screen, when you create a batch with multiple documents and then delete one of those documents and Save, it can cause the Batch.DepositAmt not to equal the Batch.CrTot. This prevents the batch from being released.
There are two workarounds for this problem:
After you delete the document from the batch, do not save when the Customer ID field is blank, just close out of the screen. Then re-launch the screen and display the batch in order to release it.
After you delete the document from the batch, use the navigational arrows to cycle back to the previously entered payment. Then save or release this batch.