Why am I being told to slow down, or seeing errors after lots of uploads?

There are limits on how fast one guest can upload, comment or like, and they reset within a minute.

There are limits on how quickly a single guest can save photos, post messages or like things. They exist to stop abuse rather than to stop you enjoying the party, and they are sized for real behaviour — machine-gunning a dozen shots and saving them is well within them.

The limits are per guest, not per network, which matters at a venue where everyone is on the same WiFi: one enthusiastic photographer cannot use up the room’s allowance.

If you do hit one, wait a minute and try again — your photos are still on your device and will resume. If you are instead told the event is full, that is a different thing entirely: see Why does it say the event is full?.