Thanks for joining this thread, @TAMurph. I'll give an update regarding the error message you received.
I've checked our reports and found out that the investigation about getting the error "Unexpected problem: -30006" when applying a credit to a customer invoice is currently tagged as closed and resolved.
In the meantime, we can follow the workaround shared by engineers. You can create an invoice first and then receive payment. This removes the error from occurring. I'll guide you on how:
- Go to the + New and then select Invoice.
- Select the name of the customer.
- Enter the necessary details.
- Once done, click on Save and close.
Once done, let's receive the payment.
- From the + New menu, select Receive Payment.
- Choose the name of the customer.
- On the Outstanding Transactions, select the invoice.
- Enter the amount received
- Click on Save and close.
Aside from that, you can also close the transaction after the error and the payment will be applied.
If you're still experiencing the said issue, I'd recommend contacting our Customer Care team. They can securely pull up your account and further investigate this matter. You can follow the steps shared by my colleague ReymondO on how to reach them.
Once the payment is received, you can now deposit it to your bank. After that, proceed with the reconciliation process. Refer to this guide for the detailed steps: Reconcile an account in QuickBooks Online.
If you have any other concerns or questions, please reach out to me again by tagging my name in your comment. I'll be right here to keep helping, @TAMurph.
