Due to technical glitch, too much people try to access the website at a time or over use of bandwidth will cause the website from loading in your computer screen. Normally the server companies used to display "service not available" notice on a white page on the website.
In this manner the American diversity visa lottery program's official website used to go out or to be down.
As we mentioned here, some technical problem or over usage of this website made this to provide the service not available message. Usually the error will be corrected in quick time and the official diversity visa lottery web site started to provide application forms and did accepted them in some hours.
To avoid such disturbance it is better to submit your entries as early as possible to try your luck to get one of the American Green card through the name selection draw.
Here is the message in the dvlottery.state.gov website regarding the opening and closing of the last year held DV-2017 visa lottery program.
"Our State Department Web site for the 2017 Diversity Visa program (DV-2017) is now open. The entry submission period for DV-2017 is from 12:00PM EDT (GMT -4) on October 1, 2015 to 12:00PM EST (GMT -5) on November 3, 2015. The entry form will only be available for submission during this period and this period only. Entries will NOT be accepted through the U.S. Postal Service."