Upgrade to Liberator of Wraeclast Supporter Pack Issue

I was unable to input my address when purchasing my Liberator of Wraeclast Supporter Pack - I had to opt out in order to get the order to go through. I was receiving "An argument was invalid"

I read somewhere else that it was mentioned to email support@grindinggear.com - I just wanted to make sure I posted it here as well.

Please let me know how we can proceed for the physical shipping