The most common cause for this is accessing the "secure" version of the website.
This is easily flagged by the secure lock icon next to the URL.
The Secure site (https) causes communication issues between our Credit Card and Hotel Interfaces. So the resolution here is to simply reload the page using the non-secure site by removing the "s" (http).
It is recommended that you bookmark this page so that you do not accidently navigate to the incorrect site in the future.
Correct full URL: http://login.skywirespa.com/