the error you are getting on the testing server means that cURL is not enabled in your php.ini file.
as this_is_me suggests, create the new php page with the following code:
<?php phpinfo(); ?>
and run this php info page on your testing server.
look for the "Loaded Configuration File" to find the location for your php.ini file.
in the php.ini file, find the following line:
and change it to:
save the php.ini file and restart your web server.
The error you are getting on the remote server is a very generic one, when it occurs, make note of the page that it is occurring on in the address bar, then add this code at line 1 of that page:
this may give us a more descriptive error message to work with.