I can no longer use gift cards on the marketplace. I always used to be able to.

[McKing]

I understand that I am unable to use a prepaid visa gift card to purchase Linden Dollars. I am not trying to do that. I always was able to use it on the marketplace as a credit card, however. The marketplace is not allowing me to. Why is this? 

Again, I Was able to use the gift card (even with the new paypal thing).

[Rolig Loon]

I think the answer is implied in this Q&A note from Linden Lab, although it doesn't answer your question "Why?"......

 

I receive the error message "This transaction cannot be completed with your chosen payment method, please purcase L$ and reattempt your purchase." when I try to make a puchase using my Credit Card or PayPal account

If you receive an error message when attempting to use your credit card or PayPal to make a Marketplace purchase, please attempt to make the purchase using Linden dollars (L$) as the payment method.

To purchase additional Linden dollars to complete your purchase:

1. On the upper-right of the page, click Buy L$
2. In the Linden Dollars (L$) box, enter the amount of Linden Dollars necessary to complete your purchase
3. Click Place Order
4. Return to the Marketplace and check out using Linden dollars as your method of payment.

Obviously, some kinds of transactions give their accounting system cholic.  Humor them.

[Lindal Kidd]

You can use your prepaid card to buy $L on a third party site.  Choose one that uses the "Linden Lab Exchange Risk API" to avoid scam sites.  I've used VirWox on occasion with good results.

Then you can use your $L in the Marketplace.