Purchasing Problems There are some common problems you might run into while purchasing access. Use Cengage Unlimited Outside the USIf you are attending a US-based institution, you can access your existing Cengage Unlimited subscription or purchase a new Cengage Unlimited subscription while living outside of the US. Purchased With the Wrong AccountWhen you purchase access for WebAssign and sign in you see a message that you have not purchased access yet. Access Code Scratched OffThe access code on a physical access card is not readable after scratching off the film covering the code.