Good evening (well it is evening here welcome to the forum.
The error message is correct. For security reasons, the default DreamHost PHP install has the allow_url_fopen option disabled. Unfortunately, this being shared hosting, you do not have access to the php.ini file to change this.
There are a number of ways to overcome this limitation. The first and probably the easiest, is to modify your code to use CURL.
Another option is to copy the PHP executable and php.ini file to your local directory and create/modify your .htaccess file to use this local version. You can then modify this local php.ini file to enable allow_url_fopen.
The third option is much like the one above, but instead of copying the DreamHost PHP executable, you compile a custom PHP executable.
Save [color=#CC0000][b]$50[/b][/color] on DreamHost hosting using promo code [color=#CC0000][b]SAVEMONEY[/b][/color] ( Click for promo code details )