Why can I not edit a sent proposal or invoice?

The short answer

Because sent commercial documents are treated as formal history, not just draft notes. Sending locks the document so the client always sees exactly what you approved.

Proposals

Sent proposals do not return to draft. If the client needs changes, create a new proposal version and send that. The earlier version stays in the history as superseded, so nothing is lost.

Invoices

Invoices are editable while they are still drafts. Once sent, the document represents billing history and payment expectations, so it locks. If a sent invoice is genuinely wrong, void it and issue a corrected one rather than trying to change it in place.

What to do instead

For proposals: create a new version from the event’s Proposal view.
For invoices: void and re-issue, or create the next billing action.

Removing an invoice you did not mean to keep

A paid invoice cannot be voided while its payments are recorded, because that money counts toward your income. The exit is deliberate, in this order:

Open the invoice. In the payments panel beside it, open each payment’s ⋯ menu and choose Delete. The status leaves Paid.
Choose Void invoice and give a reason.
Once voided, the invoice no longer counts anywhere and Delete invoice becomes available if you want it gone from your Documents.

Draft invoices can simply be deleted. Sent invoices are voided first, the same as above but without the payments step.

An invoice with a zero total is marked Paid the moment it is sent, because nothing is owed on it. It has no payments to delete, so Void invoice works on it directly — no payments step needed.

Refunds take time to become real

A payment taken online is refunded rather than deleted, and the refund is not instant. While the money is on its way back, the payment shows the amount still on its way as refund pending. It is not refunded yet, and BloomBoard will not say that it is. The payment only reads as refunded once the full amount has gone back, the card processing fee included. A partial refund keeps saying how much has gone back and how much is still refundable. Each refund is listed under the payment with its date, amount and status, so a refund that failed is visible without opening your payment provider.

If you work around document immutability incorrectly, approval and payment history become much harder to trust later.