Sandbox mode error message

[accurateweb]

I enabled Sandbox mode and entered my Sandbox API credentials. When I try to make a purchase in this mode I get the following error after entering PayPal Sandbox login info:

The link you have used to enter the PayPal system is invalid. Please review the link and try again.

Any ideas as to what I am doing wrong?

[Cristián Lávaque]

Could you please post your button's shortcode as well as the URL where the button is published (or its HTML)? Thanks.

[accurateweb]

One important detail I left out: this site is not live. It is running on my local server.

Here is the shortcode:

[s2Member-PayPal-Button level="1" ccaps="" desc="Bronze Member / description and pricing details here." ps="paypal" lc="" cc="USD" dg="0" ns="1" custom="localhost" ta="0" tp="0" tt="D" ra="0.01" rp="1" rt="M" rr="1" rrt="" rra="1" image="default" output="button" /]

[Cristián Lávaque]

Got it. Could you past here the HTML that the shortcode turns into in the page?