If you are having trouble accessing a presentation it could be for one of a number of reasons:
If you are trying to access a presentation before the date of the event, the presenter may not have made their presentation public yet.
The presentation may require a password (speak to the presenter to get the presentation password).
Make sure that the URL (web address) has been entered incorrectly.
If it is after the presentation has ended, it may be that the presenter has taken the presentation down and has decided not to make it available to download.
