Visa and MasterCard implemented rules to enhance card holder's security and reduce fraud. These rules are collectively known as PCI Data Security Standard.
To be PCI compliant, CMS implemented these standards by encrypting the credit card number that are stored in the database. All stored credit card numbers as well as newly entered ones are now encrypted and cannot be visually retrieved by anyone.
The Credit Card Processing Integration module, will be able to process cards just as before. However, if you were using the credit card fields to store card holder data for visual retrieval to be processed outside of CMS, you will no longer be able to do so.
If you need to edit a credit card number, double-clicking the credit card field will clear the old number and allow you to enter a new one.