An upload failed or is stuck

1. Tap Retry failed files at the bottom of the list, then Upload again.
2. If several fail at once, wait a few seconds — that message means the service was briefly busy, and retrying works.
3. On packed venue wifi, switching to mobile data is usually faster and more reliable.

Uploads resume file by file, so anything that already succeeded is not sent twice. Photos marked "Already added" are duplicates the event has, not errors.