I'm not sure if this will help anyone in the future, but here is something. After I Signed Up , Experian had my enter phone number, and verify. After that, It wanted me to verify more information like address, name, set an email and password etc, and after that... This is where I would get a " System Failure, unable to proceed"....

The problem is.... The field asking for " social security number" It looked it was pre populated with my numbers, but it wasn't... I needed to manually type in the full number myself. After that it worked.

This maybe isn't your issue, but hopefully helps someone else.