I have a real issue with this. A few minutes ago I was able to create a new customer record using the CIM API (developer account) without any issue. Now I am trying to create a new customer record (with all information being different). I am using the same VISA test account 4111111111111111 with the same expiration date but that should not matter. I tried using the other test visa numbers (that are 13 digits only) but of course they do not work.

What am I doing wrong here?

Thanks!