Let me give you some insights about deleting a deposit, @I am here.

It seems like you're trying to delete the invoice/sales receipt from the Undeposited Funds instead of the deposit.

The error message occurs when you’re attempting to delete an invoice/sales receipt transaction with a deposit attached to it. You'll need to select the Deposit to delete it.

Here’s how to delete a deposit:

1. Click on the Gear icon.
2. Select Chart of Accounts.
3. Choose Undeposited Funds and click View register.
4. Under the Ref No. and Type column, select the deposit.
5. Click Delete.
6. Select Yes.

Once done, all the payments in that deposit return into Undeposited Funds. 

Then, you can change the account where you deposited the invoice payment and sales receipt. Just open the transaction and select an account from the Deposit to drop-down list.

You can also run the Deposit Detail report. This report shows all your deposits, with the date, customer or vendor, and amount.

Here's how:

1. Go to Reports.
2. In the Find report by name field, type in "Deposit Detail."
3. Specify the reporting period.
4. Then click Run Report.
   
   

Reach out to me if you have any other concerns.  I’m always here to help.