Why does it say the event is full?

Each event has a photo allowance that comes with the host’s plan, and it has been reached — only the host can raise it.

Every event carries a photo allowance that comes from the plan the host chose. When the event reaches it, further uploads are refused with “This album is full for now”. It is a limit on the event as a whole, not on you, and the host can make more room from their dashboard.

The allowance counts every photo stored on the event, including ones that were never made public. There is nothing you can do from your side; tell the host, who can upgrade the event and unlock the extra capacity immediately.

If you were saving several photos at once, you may instead see a message asking you to remove a few — that means some of the batch would fit but not all of it.